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1
Osakue, Edward, Lucky Anetor i Kendall Harris. "An estimate of the pitting strength of steel materials". FME Transactions 49, nr 1 (2021): 1–20. http://dx.doi.org/10.5937/fme2101001o.
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A single expression for estimating the nominal pitting strength of steel materials, based on surface hardness, is developed from first principles for a reliability of 99% at 107 load cycles. It requires the hardness values to be measured in Vicker's hardness scale. The expression may be used for any steel material processed by hot rolling, cold drawing, quenching and tempering or case-hardening. The formulation incorporates a nominal design factor at 99% reliability which is estimated from a probabilistic model based on the lognormal probability density function. Pitting strength estimates from the expression are compared with those of American Gear Manufacturers Association (AGMA) estimates and data from other sources as indicated in Tables 3 and 4. The expression predicts lower values at low hardness but higher values at high hardness. The variance is between - 15.21% and 10.13% for through-hardened steels. For case-hardened steels, the variances range from 14.23% to 20.26% between the estimates and available data. These variances appear to be reasonable considering the many factors involved in pitting resistance. The main advantage of this study is that pitting strength of new steel materials may be estimated for initial design sizing without long and costly contact fatigue testing which of course is necessary for design validation. Also, the estimation method developed may be applied to other materials, metallic and non-metallic. Suggestions are made for estimating some pertinent pitting strength adjustment factors when considering field or service pitting strength.
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Canbula, Deniz, i Bora Canbula. "A Study of Photoneutron Reactions Using Statistical Analysis". East European Journal of Physics, nr 4 (6.12.2022): 99–103. http://dx.doi.org/10.26565/2312-4334-2022-4-08.
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The well-known inputs for determining the reaction cross section are nuclear level density (NLD) and -ray strength functions. In this work, effects of -ray strength functions and NLD models on photoneutron reactions of 76,77,78Se isotopes are analyzed by using the latest version of TALYS computer code. For -ray strength functions, macroscopic and microscopic options which are available in the TALYS, are used in the calculations. Kopecky-Uhl and Brink Axel -ray strength function models as macroscopic options, Hartree-Fock BCS tables, Hartree-Fock Bogolyubov tables and Goriely’s hybrid model as microscopic options are preferred. The statistical analysis is carried out to determine the -ray strength function that reproduces the experimental data quite well. And then, calculations of photoneutron cross section are redone by using the determined -ray strength function via the NLD models. The Constant Temperature Model (CTM), Back Shifted Fermi Gas Model (BSFGM) and Generalized Superfluid Model (GSM) are preferred to use in NLD calculations. The predictions are compared with each other and the available experimental data. EXFOR library is used to take all experimental data.
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Cong, Tianji, Madelon Hulsebos, Zhenjie Sun, Paul Groth i H. V. Jagadish. "Observatory: Characterizing Embeddings of Relational Tables". Proceedings of the VLDB Endowment 17, nr 4 (grudzień 2023): 849–62. http://dx.doi.org/10.14778/3636218.3636237.
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Language models and specialized table embedding models have recently demonstrated strong performance on many tasks over tabular data. Researchers and practitioners are keen to leverage these models in many new application contexts; but limited understanding of the strengths and weaknesses of these models, and the table representations they generate, makes the process of finding a suitable model for a given task reliant on trial and error. There is an urgent need to gain a comprehensive understanding of these models to minimize inefficiency and failures in downstream usage. To address this need, we propose Observatory, a formal framework to systematically analyze embedding representations of relational tables. Motivated both by invariants of the relational data model and by statistical considerations regarding data distributions, we define eight primitive properties, and corresponding measures to quantitatively characterize table embeddings for these properties. Based on these properties, we define an extensible framework to evaluate language and table embedding models. We collect and synthesize a suite of datasets and use Observatory to analyze nine such models. Our analysis provides insights into the strengths and weaknesses of learned representations over tables. We find, for example, that some models are sensitive to table structure such as column order, that functional dependencies are rarely reflected in embeddings, and that specialized table embedding models have relatively lower sample fidelity. Such insights help researchers and practitioners better anticipate model behaviors and select appropriate models for their downstream tasks, while guiding researchers in the development of new models.
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SARAÇOĞLU, Mustafa Halûk, Gökhan GÜÇLÜ i Fethullah USLU. "Deflection analysis of functionally graded equal strength beams". European Mechanical Science 6, nr 2 (26.06.2022): 119–28. http://dx.doi.org/10.26701/ems.1015629.
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In this study, equal strength cantilever and simply supported beams made of functionally graded material (FGM) whose material properties vary though the height direction were investigated. These equal strength cantilever FGM beams were loaded with uniformly distributed load and a point load at the tip and simply supported FGM beams were loaded with uniformly distributed loads. They have all variable cross-section and straight axis. For calculating equivalent material properties of FGMs, power law distribution and Mori-Tanaka model were used. A computer program was developed for the analysis of the problem. The dimensionless deflection values for cantilever beams and simply supported beams were obtained for different materials by the help of developed computer program. Obtained results are presented in the form of tables and graphs which may be useful for the researchers.
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Panda, Anton, Ema Nováková-Marcinčinová, Ľudmila Nováková-Marcinčinová, Tibor Krenický i Tadeusz Zaborowski. "Production from PLA Materials Processed Vertically by FDM Method RP Technology". Key Engineering Materials 756 (wrzesień 2017): 80–87. http://dx.doi.org/10.4028/www.scientific.net/kem.756.80.
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The article is focused on the aspects in samples production of sophisticated material – PLA - PolyLacticAcid, PLA plastic. The main part of the work focuses on experimental production and testing of PLA material - PolyLacticAcid plastic, printed on RepRap 3D device that works on the "open source" principle. The article presents the outcomes of test materials in the form of measurement protocols recorded in the software, the measured values in a static tensile test, marked down in tables and shown in work graphs. The article describes selected and carried out tests of mechanical properties of PLA plastics extruded in different directions in this case carried out vertically by FDM rapid prototyping method of two PLA materials such as pure without additives blended with blue dye. The tests are mainly focused on the determination of ultimate tensile strength. Based on the results obtained, the samples made of two PLA materials were compared in the end to establish which produced PLA material sample is stronger. There are outputs in the form of logs, charts and tables that provide information about the executed tests and comparisons, which were made by the authors.
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Motte, Robin, i Wim De Waele. "An Overview of Estimations for the High-Cycle Fatigue Strength of Conventionally Manufactured Steels Based on Other Mechanical Properties". Metals 14, nr 1 (10.01.2024): 85. http://dx.doi.org/10.3390/met14010085.
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Due to the time-consuming and costly nature of high-cycle fatigue experiments, correlations between fatigue strength and mechanical properties obtained through more simple and fast experiments can be interesting from an economic perspective. This review article aims to provide an overview of such relations established in the open literature from the 1980s to 2023 for conventionally manufactured steel grades. The majority of these models relate fatigue strength at a given fatigue life (often termed “fatigue limit” or “endurance limit”) to ultimate tensile strength, yield strength (both static and cyclic), hardness, elongation, reduction in area, and Charpy impact energy. Relations taking flaws such as nonmetallic inclusions into account are also discussed. Additionally, models predicting S–N curves are provided. The various estimations are presented in tables, together with the materials and test conditions for which they were established.
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Wasiana, M. Rizky Faisal Dermawan, i Iswanto Iswanto. "Analysis of Weld Joint Strength on Galvanized Material Using Rb-26 Electrode". Procedia of Engineering and Life Science 7 (13.03.2024): 295–99. http://dx.doi.org/10.21070/pels.v7i0.1469.
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Practical work is a form of education and vocational implementation that is followed by students so that students can work directly in the business world as well as industry or fabrication. Practical work aims to prepare students to become productive human beings and can immediately work in accordance with their respective fields, students can also feel the atmosphere of production and can help deal with some problems- problems experienced by Engineering professionals inside the factory. Therefore, in welding, knowledge must accompany practice, in more detail it can be said that the design of building construction and machines with welded joints, must also be planned about welding methods. This method of inspection, welding material, and type of weld to be used, based on the function of the building parts or machines designed. Based on the definition of DIN (Deutch Industrie Normen) Galvanized Welded Broken Products is the best way to assemble or connect constructions and products made from iron. This welding method is specifically performed for galvanized materials. The iron welding process requires special preparation and skills. Based on the results of fieldwork practices that have been carried out in CV. Sumber Agung Widodo, The process of making panel tables is carried out into several stages, namely the hollow iron cutting, 45-degree galvanized angle cutting, iron plate cutting, elbow iron cutting, splicing by welding, frame painting, and mounting a series of panels to the finished panel table. The materials used are hollow iron, iron plate, elbow iron, iron paint, wheels. The tools used are ac current welding machines, grinders and elbow rulers. Stage
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Gnatowski, Adam, Agnieszka Kijo-Kleczkowska, Rafał Gołębski i Kamil Mirek. "Analysis of polymeric materials properties changes after addition of reinforcing fibers". International Journal of Numerical Methods for Heat & Fluid Flow 30, nr 6 (29.05.2019): 2833–43. http://dx.doi.org/10.1108/hff-02-2019-0107.
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Purpose The issues concerning the prediction of changes in properties of polymer materials as a result of adding reinforcing fibers are currently widely discussed in the field of polymer material processing. This paper aims to present strengths and weaknesses of composites based on polymer materials strengthened with fibers. It touches upon composite cracking at the junction of a matrix and its reinforcement. It also discusses the analysis of changes in properties of chosen materials as a result of adding reinforcing fibers. The paper shows improvement in the strength of polymer materials with fiber addition, which is extremely important, because these types of composites are used in the aerospace, automotive and electrical engineering industries. Design/methodology/approach Comparing the properties of matrix strength with fiber properties is practically impossible. Thus, fiber tensile strength and composite tensile strength shall be compared (González et al., 2011): tensile (glass fiber GF) = 900 [MPa], elongation ΔL≈ 0; yield point (polyamide 66) = 70−90 [MPa], elongation Δ[%] = 3,5-18; tensile (polyamide 66 + 15% GF) = 80-125 [MPa], elongation Δ[%] ≈ 0; tensile (polyamide 66 + 30% GF) = 190 [MPa], elongation Δ[%] ≈ 0; yield point (polyamide 6) = 45-85 [MPa], elongation Δ[%] = 4-15; tensile (polyamide 6 + 15% GF) = 80-125 [MPa], elongation Δ[%] ≈ 0; tensile (polyamide 6 + 30% GF) = 95-130 [MPa] elongation Δ[%] ≈ 0. Comparison of properties of selected polymers and composites is presented in Tables 1−10 and Figures 1 and 2. The measurement methodology is presented in detail in the paper Kula et al. (2018). The increase in fiber content (to the extent discussed) leads to the increase in yield strength stresses and hardness. The value of yield strength for polyamide with the addition of fiberglass grows gradually with the increase in fiber content. The hardness of the composite of polyamide with glass balls increases together with the increase in reinforcement content. The changes of these values do not occur linearly. The increase in fiber content has a slight impact on density change (the increase of about 1 g/mm3 per 10 per cent). Findings The use of polymers as a matrix allows to give composites features such as: lightness, corrosion resistance, damping ability, good electrical insulation and thermal and easy shaping. Polymers used as a matrix perform the following functions in composites: give the desired shape to the products, allow transferring loads to fibers, shape thermal, chemical and flammable properties of composites and increase the possibilities of making composites. Fiber-reinforced polymer composites are the effect of searching for new construction materials. Glass fibers show tensile strength, stiffness and brittleness, while the polymer matrix has viscoelastic properties. Glass fibers have a uniform shape and dimensions. Fiber-reinforced composites are therefore used to increase strength and stiffness of materials. Polymers have low tensile strength, exhibit high deformability. Polymers reinforced by glass fiber have a high modulus of elasticity and therefore provide better the mechanical properties of the material. Composites with glass fibers do not exhibit deformations in front of cracking. An increase in the content of glass fiber in composites increases the tensile strength of the material. Polymers reinforced by glass fiber are currently one of the most important construction materials and are widely used in the aerospace, automotive and electro-technical industries. Originality/value The paper presents the test results for polyethylene composites with 25 per cent and 50 per cent filler coming from recycled car carpets of various car makes. The tests included using differential scanning calorimetry, testing material hardness, material tensile strength and their dynamic mechanical properties.
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Ghodke, Prof Kiran. "Preparing Design Aids for Fe550 Steel for M25 Grade of using Concrete from SP-16". International Journal for Research in Applied Science and Engineering Technology 12, nr 4 (30.04.2024): 3445–56. http://dx.doi.org/10.22214/ijraset.2024.60623.
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Abstract: The main purpose of this paper presentation is to develop design aids for Fe 550 grade of steel from sp 16 handbook. The design aids prepared will be in the form of tables which will benefit in the calculations of various components of concrete structures. To prepare design aids for FE550, you would need to focus on creating resources that cover various aspects related to structural design, specifically for materials like Fe550. Design aids typically include information on material strength, stressstrain relationships, flexural members, compression members, shear and torsion, development length, anchorage, deflection calculation, and general tables, explanations of the basis of preparation, and worked examples illustrating the use of the design aids.
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Ghodke, Prof Kiran. "Preparing Design Aids for Fe550 Steel for M20 Grade of Concrete Using SP-16". International Journal for Research in Applied Science and Engineering Technology 12, nr 4 (30.04.2024): 3646–57. http://dx.doi.org/10.22214/ijraset.2024.60621.
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Abstract: The main purpose of this paper presentation is to develop design aids for Fe 550 grade of steel from sp 16 handbook. The design aids prepared will be in the form of tables which will benefit in the calculations of various components of concrete structures. To prepare design aids for FE550, you would need to focus on creating resources that cover various aspects related to structural design, specifically for materials like Fe550. Design aids typically include information on material strength, stressstrain relationships, flexural members, compression members, shear and torsion, development length, anchorage, deflection calculation, and general tables, explanations of the basis of preparation, and worked examples illustrating the use of the design aids.
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Adin, Hamit, i Mehmet Şükrü Adin. "Effect of particles on tensile and bending properties of jute epoxy composites". Materials Testing 64, nr 3 (1.03.2022): 401–11. http://dx.doi.org/10.1515/mt-2021-2038.
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Abstract In this investigation, mechanical properties of composite materials produced from woven jute type were investigated. These composites were produced in the form of epoxy adhesive layers by using hand lay-up method in which aluminum, mica and ceramic particles were added into epoxy as a structural adhesive by 2, 4 and 6 wt%. Samples produced according to ASTM D procedures were subjected to tensile and three point bending loads to examine the effect of the particles. Experimental results were presented in tables and graphs. As a result, it was observed that the tensile and bending failure loads of the composite materials obtained by using the particle reinforced adhesive increased. Also, the biggest rise in tensile strength was achieved with 4 wt% aluminum and the biggest increase in bending strength was observed for 2 wt% aluminum particles.
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Gil, Lucero, Sheyla Ruiz, José Rodriguez i Juan Vise. "Influence of Cement on Concrete Mix Designs through Sustainability Indicators". Materials Science Forum 1058 (5.04.2022): 107–11. http://dx.doi.org/10.4028/p-2fw248.
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Internationally, the most widely used concrete mix design methods are the American Concrete Institute, Department of Environment, Indian Standard, Fineness Modulus and Walker. These methods propose the dosage of materials from tables and graphs developed from multiple experiments and generalize the designs to achieve optimum strength, durability, and quality performance. However, sustainability does not contemplate the design, especially cement, which is responsible for CO2 emissions and the cost of concrete. The study analyzed the procedure and dosage of five methods for a 20 MPa strength concrete mix in the laboratory and applied them to beams and columns in a multi-family building using sustainability indicators. The results indicate that the IS method uses water efficiently, is more economical, and requires less cement, while the ACI method generates a positive environmental and social impact due to the efficient consumption of materials.
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Nováková-Marcinčinová, Ema, Anton Panda i Ľudmila Nováková-Marcinčinová. "Sophisticated Production from Organic PLA Materials Processed Horizontally by Fused Deposition Modeling Method". Key Engineering Materials 756 (wrzesień 2017): 88–95. http://dx.doi.org/10.4028/www.scientific.net/kem.756.88.
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The article focuses on the samples production of organic material PLA-PolyLacticAcid – bioplastic. The main part describes the experimental testing of PolyLacticAcid plastic and sample production by Fused Deposition Modeling, Rapid Prototyping technology. The article presents selected carried out tests of mechanical properties focused mainly on the determination of ultimate tensile strength of two PLA-BIO plastic extruded horizontally along the width produced by FDM method, Rapid Prototyping. The authors of this article present their results of test materials in the form of measurement protocols recorded in software, the measured values in a static tensile test, recorded in tables and shown in work graphs. Based on the results of the two samples produced from PLA biomaterials and compared to determine which PLA – bioplastic is stronger.
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Okta Saputa, Dialis, Ferry Setiawan i Dhimas Wicaksono. "THE EFFECT OF VARIATION OF TEMPERATURE ON PULL TEST OF FIBERGLASS FIBER COMPOSITE MATERIALS WITH VACUUM ASSISTED RESIN INFUSION (VARI)". Teknika STTKD: Jurnal Teknik, Elektronik, Engine 9, nr 1 (27.07.2023): 128–37. http://dx.doi.org/10.56521/teknika.v9i1.868.
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To determine the effect of temperature variations on mixing fiberglass composite resin materials with the vacuum infusion method in the Tensile test. To determine the effect of the lowest and best temperature variations on mixing fiberglass composite resin materials with the vacuum infusion method on fotomikro. Variation fixed resin; polyester, fiber; fiberglass, vacuum; vacuum Infusion. Variable temperature of mixing resin 30˚C, 40˚C, and 50˚C. In this study, the vacuum infusion method was used, where the researcher made a specimen using the Vacuum Assisted Resin Infusion (VARI) process. In the VARI process, dry fiber is placed between the fixmold and the plastic bag, then the resin is injected after the space inside the plastic bag is under low pressure and the process continues until all parts of the fiber are wetted by the resin. After the specimen is made, then a tensile test is carried out to determine the mechanical strength of the specimen being tested. Then analyze the tensile test data using the equations used and displayed in the form of graphs and tables. This study was used to determine the effect of fiberglass composites with the vacuum infusion method on the tensile strength test. results of Tensile testing of fiberglass fiber composites and temperature variations of 30°C, 40°C, and 50°C. From the table it can be seen that the specimen with the best performance is found in the specimen with a temperature variation of 50°C, where the load that can be withheld reaches 508.56 kgf. So for maximum tensile strength it produces 11.07 MPa. Then on the specimen with a temperature variation of 40°C the best performance is 361.95 kgf. So for maximum tensile strength it produces 8.46 MPa. In specimens with a temperature variation of 30°C the best performance is 251.10 kgf. So for a maximum tensile strength of 5.67 Mpa. The average yield strength shows the results of the Tensile test of each variation, totaling 9 specimens. For the highest yield strength, a value of 9.67 MPa was obtained at a temperature variation of 50°C and for the lowest yield strength, a value of 4.13 MPa was obtained at a temperature variation of 30°C. Tensile test specimens have results where the highest yield strength or yield strength is obtained by specimens with a temperature variation of 50°C and as the stress increases, the yield strength value increases, and for the tensile strength of the material or tensile strength which has the highest value in the test, the specimens with 50°C temperature variation. Thus, the effect of temperature treatment is significant on the increase in tensile strength, but if the temperature is 30°C it will decrease the tensile strength, as at 30°C it produces an average tensile strength of 4.62 MPa. The results of the microphoto test show that at a temperature variation of 50°C there are a few voids while the 30°C variation has too many voids. Micro photo testing aims to determine the content in the composite.
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Tera, Melania, Octavian Bologa, Radu Eugen Breaz i Sever Gabriel Racz. "Theoretical and Experimental Researches Regarding Multilayer Materials Used for Incremental Forming". Applied Mechanics and Materials 555 (czerwiec 2014): 413–18. http://dx.doi.org/10.4028/www.scientific.net/amm.555.413.
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Although this represents a relatively recent development in the industry, the composite multilayer sheets are currently encountered in almost all industrial domains, due to the density, mechanical strength and energy absorption properties that are higher than those of the blanks realised from a single material. These materials are useful especially in domains such a the automotive industry, where the vehicles must fulfil simultaneously conditions of increased passenger safety, increased comfort, increase of the loading capacity in conditions of a reduced energy consumption. First of all the paper shows the types of multilayer sheets and their areas and areas of use, then the paper analyzes the experimental results for an example of such a sheets namely bimetallic tables. The materials are subjected to tensile testing and we are determined limit deformation curves. The experimental result of incremental forming on a CNC milling machine bimetallic sheet is also presented.
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Гершман, Иосиф, Iosif Gershman, Александр Миронов, Aleksandr Mironov, Евгений Гершман i Evgeniy Gershman. "NEW ALUMINUM ANTIFRICTION ALLOYS INSTEAD OF BRONZES FOR MONOMETALLIC BEARINGS OPERATING UNDER CONDITIONS OF BOUNDARY FRICTION". Bulletin of Bryansk state technical university 2016, nr 4 (28.12.2016): 22–31. http://dx.doi.org/10.12737/23158.
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In the paper there is presented an investigation on the subject of the substitution of materials used for manufacturing monometallic one-piece sliding bearings. The most widely used material for their manufac-turing is bronze of BrO4Ts4$17 grade which has rather high values of antifriction and strength properties. A whole complex of materials based on aluminum alloys is under consideration. There were investigated eight experimental alloys different with chemistry. In the paper there is described a procedure for carrying out experimental investigations. The comparative tables of the influence of these or those elements upon tribological properties are shown. An evident advantage of aluminum alloys over a compared material – bronze of BrO4Ts4S17 grade is identified. The following tribo-technical properties of experimental alloys such as score-resistance, conformability, durability, frictional moment are considered. Key words: aluminum antifriction alloys, bronze, stress-strain properties, strength, hardness, tribotechnical properties, conformability, scoreresistance, durability, secondary structures.
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Boron, Pawel, Jaroslaw Chelmecki, Joanna Maria Dulinska, Nadzieja Jurkowska, Bartlomiej Ratajewicz, Piotr Stecz i Tadeusz Tatara. "On the Possibility of Using 3D Printed Polymer Models for Modal Tests on Shaking Tables: Linking Material Properties Investigations, Field Experiments, Shaking Table Tests, and FEM Modeling". Materials 16, nr 4 (9.02.2023): 1471. http://dx.doi.org/10.3390/ma16041471.
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In this article, the possibility and the pertinence of using 3D printed polymeric materials for models in modal tests on shaking tables were recognized. Four stages of the research have been linked: The material properties investigation, the field experiment on the modal properties of the reinforced concrete chimney (a prototype), the shaking table tests on the modal properties of the 3D printed polymer model of the chimney, scaled according to the similarity criteria, and the numerical calculations of the FE model of the 3D printed mockup. First, the investigation of the properties of 3D printed polymer materials revealed that the direction of lamination had no significant effect on the modulus of elasticity of the material. This is a great benefit, especially when printing models of tall structures, such as chimneys, which for technical reasons could only be printed in a spiral manner with the horizontal direction of lamination. The investigation also proved that the yield strength depended on the direction of the lamination of the specimens. Next, the natural frequencies of the chimney, assessed through the field experiment and the shaking table tests were compared and showed good compatibility. This is a substantial argument demonstrating the pertinence of using 3D printed polymer materials to create models for shaking table tests. Finally, the finite element model of the 3D printed polymer mockup was completed. Modal properties obtained numerically and obtained from the shaking table test also indicated good agreement. The presented study may be supportive in answering the question of whether traditional models (made of the same material as prototypes) used in shaking table tests are still the best solution, or whether innovative 3D printed polymer models can be a better choice, in regard to the assessment of the modal properties and the dynamic performance of structures.
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Egamberdiev, Elmurod, Khurshid Khaydullaev, Sevinch Abdurazakova, Qodirjon Khoshimov, Olimjon Muratkulov, Khusan Tilovov, Bekmurod Rakhimjonov i Muqaddas Alieva. "Composite papers based on natural polymers". E3S Web of Conferences 497 (2024): 03031. http://dx.doi.org/10.1051/e3sconf/202449703031.
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In this study, cellulose was extracted from Heliánthus tuberósus (Jerusalem artichoke) stems, and its quality indicators were thoroughly investigated. The isolation process involved the removal of impurities and non-cellulosic components, resulting in a purified cellulose sample suitable for further analysis and application.To explore the potential of Heliánthus tuberósus cellulose, composite paper was produced by incorporating basalt fiber into the cellulose matrix. The resulting paper was subjected to comprehensive testing to evaluate its mechanical properties, with a particular focus on tensile strength and tensile length.The tensile strength of the composite paper was determined using standardized testing methods, providing quantitative data on the material's ability to withstand applied forces without breaking or deforming. Tensile length, on the other hand, refers to the maximum elongation the paper can undergo before rupture occurs. These properties were assessed to gauge the overall performance and suitability of the composite paper for various applications.The obtained results were presented in a clear and concise manner, utilizing tables and graphs to facilitate data interpretation and comparison. Tables allowed for the tabulation of the measured tensile strength and tensile length values, providing a comprehensive overview of the material's mechanical characteristics. Graphs were employed to visualize trends, patterns, and potential correlations between different variables, aiding in a deeper understanding of the composite paper's behavior under various loading conditions.
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de Morais, Jorge Fernandes, Assed Naked Haddad i Laia Haurie. "Analysis of the Behavior of Carbon Nanotubes on Cementitious Composites". ISRN Nanomaterials 2013 (27.08.2013): 1–17. http://dx.doi.org/10.1155/2013/415403.
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Nanotechnology has brought significant innovations in science and engineering. Carbon nanotube has been considered a new and outstanding material in nanoscience field with great potential application in the construction industry. The main objective of this study is to analyze the behavior of cementitious materials produced with the insertion of carbon nanotubes of multiple walls in different concentrations and compare their physic-mechanical properties with plain mortar. This research covers the examination of nanoscale cement products and the use of carbon nanotubes to increase the strength and durability of cementitious composites. Three different ratios of carbon nanotubes have been searched: 0.20, 0.40, and 0.60%. To evaluate the mechanical properties of the samples, destructive and nondestructive tests were carried out to obtain compressive strength, tensile strength by diametrical compression, and dynamic modulus of elasticity as well as to determine their deformation properties. Methods of instrumentation such as scanning electron microscopy and porosity were also used in the analysis of microstructure of the materials. The study presents graphs, tables, and figures describing the behavior of CNT added to mortars samples, allowing a better understanding of the use of this new material in the construction industry.
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Madival, Abhishek Sadananda, Deepak Doreswamy, Shripathi Adiga Handady, Krishna Raghava Hebbar i Shobha Karabylu Lakshminarayana. "Investigation of the Mechanical and Liquid Absorption Properties of a Rice Straw-Based Composite for Ayurvedic Treatment Tables". Materials 15, nr 2 (14.01.2022): 606. http://dx.doi.org/10.3390/ma15020606.
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Managing rice crop stubble is one of the major challenges witnessed in the agricultural sector. This work attempts to investigate the physical, mechanical, and liquid absorption properties of rice straw (RS)-reinforced polymer composite for assessing its suitability to use as an ayurvedic treatment table. This material is expected to be an alternative for wooden-based ayurvedic treatment tables. The results showed that the addition of rice straw particles (RSp) up to 60% volume in epoxy reduced the density of the composite material by 46.20% and the hardness by 15.69%. The maximum tensile and flexural strength of the RSp composite was 17.53 MPa and 43.23 MPa, respectively. The scanning electron microscopy (SEM) analysis showed deposits of silica in the form of phytoliths in various size and shapes on the outer surface of RS. The study also revealed that the water absorption rate (WA) was less than 7.8% for the test samples with 45% volume of RSp. Interestingly the test samples showed greater resistance to the absorption of Kottakal Dhanvantaram Thailam (<2%). In addition, the developed samples showed resistance towards bacterial and fungal growth under the exposure of treatment oils and water.
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Balcha Balla, Tamrat, Nisha MaryJoseph i Anteneh Belete. "In Vitro Evaluation of Native Taro Boloso-I Starch as a Disintegrant in Tablet Formulations". Advances in Materials Science and Engineering 2021 (24.12.2021): 1–10. http://dx.doi.org/10.1155/2021/7576730.
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Introduction. In drug delivery, solid dosage forms, of which tablet is the commonest, are still the leading preferences. An area of research focus in tablet drug delivery is the search for tablet excipients. This study was aimed at evaluating and optimizing native Taro Boloso-I starch as a tablet disintegrant. Methods. The response surface method with central composite design (CCD-RSM) was used for the analysis and optimization of the concentration of native Taro Boloso-I starch and compression force. Wet granulation method was used for the preparation of paracetamol tablets. The response variables considered were tablet crushing strength, friability, and disintegration time. Results and Discussion. Both the native Taro Boloso-I starch concentration and compression force had increasing effect on the tablet breaking force. The friability of the tablets was shown to decrease with increasing levels of the disintegrant concentration. On the other hand, compression force had a decreasing effect on friability in the investigated range. The disintegration time of the tablets was found to decrease with the concentration of the starch. The paracetamol tablets prepared with the optimized levels of native Taro Boloso-I starch and compression force showed tablet breaking force of 116.24 N, friability of 0.153%, disintegration time of 1.36 min, disintegration efficiency ratio of 562.3 N/(%Min), and comparative disintegration efficiency ratio of 13.6 with respect to commercial potato starch. Conclusions. The tablets exhibited improved crushing strength, friability, in vitro disintegration time, and disintegration efficiency ratio which suggest the novel applicability of the native Taro Boloso-I starch as an efficient pharmaceutical tablet disintegrant.
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Sam, Joel. "Compressive Strength of Concrete using Fly Ash and Rice Husk Ash: A Review". Civil Engineering Journal 6, nr 7 (1.07.2020): 1400–1410. http://dx.doi.org/10.28991/cej-2020-03091556.
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Decreasing our over-reliance on cement as an ingredient in the making of concrete due to its contribution to the CO2 emissions has led to numerous researches been conducted to find suitable replacement for cement in concrete mixes. Materials like fly ash, ground granulated blast furnace slag, silica fume, rice husk ash and metakaolin among others have been identified as materials that can at the very least be used as a replacement for cement in concrete mix. These materials are referred to as supplementary cementitious materials (SCMs). This paper reviewed the work that has been done on the use of fly ash and rice husk ash as partial replacements for concrete, its chemical composition and its effect on the compressive strength of concrete. Charts, tables and figures were employed as tools to study the various chemical compounds of fly ash and rice husk ash. It was seen that depending on how the coal or rice husk was initially processed the percentage of some of the minor compounds like Sodium oxide (Na2O), Titanium oxide (TiO2) and Phosphorus pentoxide (P2O5) were sometimes very low or not recorded as part of the final product. The data on the compressive strength of concrete after fly ash and rice husk ash had been added in percentage increments of 0%, 10%, 20%, 30%, 40%, 50% and 0%, 5%, 7.5%, 10%, 12.5%, 15% respectively analysed over a minimum period of 7 days and a maximum period of 28 days found out that the optimal percentage partial replacement of fly ash and rice husk ash for a strong compressive concrete strength is 30% of fly ash and 7.5% of rice husk ash.
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Ponomarev, O. I., Yu F. Panchenko, M. A. Mukhin, A. S. Vetkov i A. Yu Dozorova. "Effects of sample dimensions in compressive strength tests of masonry wall products". Bulletin of Science and Research Center of Construction 39, nr 4 (17.12.2023): 82–94. http://dx.doi.org/10.37538/2224-9494-2023-4(39)-82-94.
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Introduction. State standards for testing ceramic masonry wall materials of plastic molding establish grinding as the main method of smoothening supporting (loaded) surfaces. Therefore, studies were conducted on the effect of sample dimensions on the compressive strength of tested masonry products. The effect of a scale factor on the measured strength of brick and stone has so far been only partially reflected in the standard for test methods (GOST 8462 “Wall materials. Methods for determining compressive and bending strength”). According to both Russian and foreign specialists, shape factors values, provided in EN 772-1 European standard “Methods of test for masonry units. Part 1. Determination of compressive strength” need to be adjusted as they do not take into account the void ratio of masonry products and the sample material type.Aim. To assess the effects, caused by the geometric dimensions of masonry product samples, as well as the void ratio and other characteristics, on compressive strength according to the results of laboratory tests. Materials and methods. As a result of conducted control tests of ceramic and silicate single and thickened bricks with a void ratio of up to 27 %, measured values of product compression strength were compared to determine the value of transition coefficients.Results. The performed studies confirmed the shape coefficients, adopted in EN 772-1, to require an adjustment. Based on the results of studies, conducted in Russia and abroad, conclusions and recommendations were made to take into account the dimensions of tested samples during strength tests.Conclusion. Performed studies and analysis of experimental results have demonstrated that in order to increase the accuracy of determining the strength of test samples, taking into account their shape and void ratio, it is necessary to have several tables with shape factors. Currently, until reliable data about the void ratio effect of the masonry material on test results are obtained, it is advisable to take into account only the height of the sample (“longitudinal bending”).
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Fóris, Ildikó, i Gábor Mucsi. "INFLUENCE OF RAW MATERIAL PROPERTIES ON WASTE-BASED GLASS FOAM". Rudarsko-geološko-naftni zbornik 38, nr 4 (2023): 75–83. http://dx.doi.org/10.17794/rgn.2023.4.7.
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Glass foam tablets were prepared by using mixed glass bottles (green, brown, and white), eggshell waste as a foaming agent, Na-bentonite as binder material, and red mud as an additive, respectively. The influence of the amount of red mud and fly ash on the properties (foaming temperature, mechanical strength, specimen density and porosity, thermal conductivity) of the tablets was studied. The foamed tablets contained 2.5 wt % binder material, 0.1 wt % foaming agent, 5 wt % fly ash, and red mud as additives in different ratios (0 – 40 wt %). After homogenization, the ground raw materials were pressed into tablets at 30 MPa using a hydraulic piston press. The products were heat treated at different temperatures with different heating rates. The final product’s properties were measured (specimen density, thermal conductivity, and mechanical strength through falling and abrasion resistance tests). The most convenient results were shown at 5 wt % red mud in this case, the specimen density and thermal conductivity were the lowest, the values were 0.3 g/cm3 and 0.036 W/mK. If 5 wt % of fly ash was added to the mixture the density value stayed the same, the thermal conductivity increased to 0.048 W/mK, but the mechanical strength of the tablets rapidly increased.
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Mužíková, Jitka, Sandra Muchová, Alena Komersová i Václav Lochař. "Compressibility of tableting materials and properties of tablets with glyceryl behenate". Acta Pharmaceutica 65, nr 1 (1.03.2015): 91–98. http://dx.doi.org/10.1515/acph-2015-0006.
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Abstract The paper studies the compressibility of directly compressible tableting materials with dry binders, spray-dried lactose and microcrystalline cellulose, and glyceryl dibehenate at various concentrations. Compressibility was evaluated by means of the energy profile of compression and tensile strength of tablets. Release rate of the active ingredient, salicylic acid, from the tablets was also examined. In the case of microcrystalline cellulose, a higher concentration of glyceryl dibehenate increased the strength of tablets, while this did not occur in the case of spray-dried lactose. Increasing concentration of glyceryl dibehenate prolonged the release of salicylic acid; however, no statistically significant difference was found compared to the type of the dry binder used
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Garmsiri, Karim, i Mostafa Jalal. "Multiobjective optimization of composite cylindrical shells for strength and frequency using genetic algorithm and neural networks". Science and Engineering of Composite Materials 21, nr 4 (1.09.2014): 529–36. http://dx.doi.org/10.1515/secm-2013-0208.
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AbstractIn this paper, the optimal fiber orientations relative to the principle axis of composite cylindrical shell composed of four and six layers were determined so that the natural frequency and strength of the shell are optimized. For this purpose, first, the free vibration analysis of the shell was carried out based on 3D elasticity. Then, for calculation of the strength objective function, the inverse form of Tsai-Hill yield criteria was used and the functions of strength and frequency were developed in terms of fiber orientation. Once the correctness of the above solutions was ensured, the objective functions were modeled with artificial neural network (ANN). The model made was then introduced into genetic algorithm (GA) and the maximum fitness function and optimal staking sequence of the layers with respect to the fibers angles were obtained. Optimal solutions obtained by combination of ANN and GA are compared to the solutions obtained by analytical solution and GA; eventually, the tables and diagrams are presented and different fiber orientations as optimization solutions are presented as the final results of the composite shell analysis.
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Sezgin, Hande, i Omer B. Berkalp. "Analysis of the effects of fabric reinforcement parameters on the mechanical properties of textile-based hybrid composites by full factorial experimental design method". Journal of Industrial Textiles 48, nr 3 (6.11.2017): 580–98. http://dx.doi.org/10.1177/1528083717740764.
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In this study, the effect of some fabric reinforcement parameters (fabric direction, yarn type and stacking sequence) on the mechanical properties of textile based hybrid composites are analysed by using full factorial experimental design method. The analysis of the results is achieved by using Minitab 17 software program. One factor (fabric reinforcement direction) with two levels (warp direction and weft direction) and two factors (yarn type and stacking sequence) with three levels (jute/glass, jute/carbon, glass/carbon and consecutive, low strength inside, high strength inside) are selected as the reinforcement design. Full factorial experimental design analysis results indicate that, the highest tensile and impact strength values among the experimental design are realised when samples are taken from the warp direction and E-glass/carbon combination is chosen as the yarn (material) type. Moreover, it is verified that while higher tensile strength is achieved by placing higher strength fabrics to the inner layers, higher impact strength is achieved by placing high strength fabrics to the outer layers of hybrid composite structures. Analysis of variance tables also show that at 95% confidence level, the effects of the factors are statistically significant ( p < 0.05).
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Křížová, Klára, i Rudolf Hela. "Evaluation of the Modulus of Elasticity of Different Types of Concrete Compared with Eurocode 2". Key Engineering Materials 677 (styczeń 2016): 181–85. http://dx.doi.org/10.4028/www.scientific.net/kem.677.181.
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The comparison of really measured compressive strength static modulus of elasticity with table values stated in Eurocode 2 is essential part of the paper. Since the standard draws from modulus of elasticity - concrete strength class, the set compressive strengths will be classified in concrete particular classes. Experimental part was based on several concrete design compositions differing in particular input raw-materials. Monitored values were set with concretes in different ages with final value 180 days. The experiment tries to demonstrate the impossibility of static modulus of elasticity derivation from table values which do not match the present-date produced concretes.
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Datta, Mallika, Devarun Nath, Srijan Das i Mainul Malitha. "Suitable stacking sequence of glass fibre reinforcements for specific application of composite using Taguchi design and finite element method". Journal of Industrial Textiles 52 (sierpień 2022): 152808372211283. http://dx.doi.org/10.1177/15280837221128312.
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The effect of stacking sequence of the various forms of glass fibre reinforcement on unsaturated polyester resin composite subjected to tensile and flexural loading was investigated. The Taguchi statistical technique had been used to identify a sustainable stacking sequence with unidirectional glass filament structure, glass fibre chopped strand mat, and woven glass roving mesh as reinforcement. The study used top, middle, and bottom layer positions of the reinforcing material stack inside the composite as control factors for tensile strength, and as well as flip (turning the face of the sample about the testing probe) for flexural strength. Response tables and analysis of variance were used to identify the most influential factors, and response graphs indicated the most important level for control factors. It was demonstrated that the location with the highest contribution for tensile strength was the middle layer, and in the instance of flexural loading, the bottom layer rear to the probe of the universal testing machine was the primary control factor. The strongest level was found to be one made of chopped strand mat sandwiched between two cross-oriented unidirectional filament structures. The uniqueness of this research is to establish the optimal way to stack reinforcements in superstructures such as walls, tables, beams that are only partially supported, poles, and boats, considering the different types of loads and the directions in which the forces act. The Finite Element Method (FEM) was used, to simulate the findings.
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Hasan, Tawsif Mohammad, Levi Gilbert, Srinivas Allena, Josiah Owusu-Danquah i Anthony Torres. "Development of Non-Proprietary Ultra-High Performance Concrete Mixtures". Buildings 12, nr 11 (3.11.2022): 1865. http://dx.doi.org/10.3390/buildings12111865.
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The development of non-proprietary Ultra-High Performance Concrete (UHPC) is one way to reduce the initial cost of construction. However, workability is a major issue for which such mixtures are not practical in field conditions. Ultra-high performance cannot be achieved in field conditions if the concrete is not placed, finished, and compacted properly during placement. In this research, six UHPC mixtures were developed (three with steel fibers and three without fibers) using materials which are readily available on the local marketplace with water-to-cementitious materials ratios ranging between 0.17 to 0.30. The workability was determined using standard ASTM flow table apparatus, and specimens were prepared to determine compressive strength, splitting tensile strength, and permeable porosity. Flow table test exhibited flow values greater than 250 mm. Such high workability of the mixtures was achieved by optimizing the silica fume content and water reducing admixture dosage. These mixtures exhibited compressive strengths greater than 120 MPa and splitting tensile strengths greater than 5.10 MPa in both ambient and elevated curing temperatures. Results indicated that UHPC can be produced with a water-to-cementitious materials ratio as high as 0.30. Steel fibers helped to increase splitting tensile strength due to fiber-matrix interactions. Very low permeable porosity (1.7–16.7%) was observed which indicates superior durability due to the significant reduction of ingress of deleterious ions.
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Abdellah, Mohammed Y., Mohamed K. Hassan, Ahmed F. Mohamed i Khalil Abdelrazek Khalil. "A Novel and Highly Effective Natural Vibration Modal Analysis to Predict Nominal Strength of Open Hole Glass Fiber Reinforced Polymer Composites Structure". Polymers 13, nr 8 (12.04.2021): 1251. http://dx.doi.org/10.3390/polym13081251.
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Glass fiber reinforced polymer (GFRP) composite laminates are considered the key material in many industries such as the infrastructure industries and the aerospace sector, and in building structures due to their superior specific strength and lightweight properties. The prediction of specimens’ nominal strength with open holes is still an attractive and questionable field of study. The specimen size effect is referred to its strength degradation due to the presence of holes when specimen geometry gets scaled. The non-destructive test used to measure the nominal strength of such material is a great tool for fast selection purposes, but not secure enough for several purposes. Furthermore, the destructive tests which are more expensive and time-consuming should be avoided in such structures. The present work aims to predict the nominal strength of open-hole GFRP’s composite using modal analysis of their natural frequency as non-destructive tests. At this end, the natural frequency, which is measured using modal analysis procedures, is combined with both linear elastic fracture mechanics (LEFM) and the theory of elasticity to predict the nominal strength of open-hole composite laminates. This advanced model employs two parameters of surface release energy resulting from a simple tension test and Young’s modulus based on vibration modal analysis. It is well established that these types of materials are also subjected to a size effect in dynamic response. Inversely to the known static loading size effect, the size effect in dynamic response increases with specimen size. The novel model gives excellent and acceptable results when compared with experimental and finite element ones. Size effects curves of a nominal strength of these laminates have a very close relative value with those obtained from finite element and analytical modeling. Moreover, the received design tables and graphs would be highly applicable when selecting suitable materials for similar industrial applications.
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Anciferov, S., A. Karachevceva, E. Sychyov i A. Obernihin. "DETERMINATION OF THE STRENGTH OF A CONE CRUSHER STAND". Bulletin of Belgorod State Technological University named after. V. G. Shukhov 7, nr 8 (16.08.2022): 92–102. http://dx.doi.org/10.34031/2071-7318-2022-7-8-92-102.
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The state of the direction of crushing materials in the mining industry is considered. The method of static calculation for the strength of the frame of the cone crusher KSD – 900 in two positions is given. The application of the machine at various stages of crushing is demonstrated. The comparison with other crushers of the mining industry is carried out. The design and operating principle of the digital twin of the cone crusher of medium crushing are described. The advantages and disadvantages of the machine are given. The finite element method of the CAD/CAM/CAE system NX and the module “Advanced Simulation” are considered. Today’s significance of engineering analysis is described. The calculation schemes of the cone crusher stand in several static positions are given: at the moment of lifting the stationary cone and lid, when non-crushing material enters and when the stationary cone and lid of the cone crusher are lowered. The idealization of the frame in the CAD/CAM/CAE NX system and the “Advanced Simulation” module of the cone crusher are shown to reduce the load on the calculating machine. It leads to a reduction in the calculation time of the model. Tables of external loads under the own weight of the working units of the machine are presented. The calculation of comparing the maximum design stresses with those allowed for the selected material and determining the safety factor of stand is shown.
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van Veen, B., K. van der Voort Maarschalk, G. K. Bolhuis, K. Zuurman i H. W. Frijlink. "Tensile strength of tablets containing two materials with a different compaction behaviour". International Journal of Pharmaceutics 203, nr 1-2 (sierpień 2000): 71–79. http://dx.doi.org/10.1016/s0378-5173(00)00450-6.
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Leszczuk, Tomasz. "Evaluation of the Fertilizer Granules Strength Obtained from Plate Granulation with Different Angle of Granulation Blade". Acta Mechanica et Automatica 8, nr 3 (1.09.2014): 141–45. http://dx.doi.org/10.2478/ama-2014-0025.
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Abstract The goal of the paper was to assess the strength of the fertilizer granules obtained by non-pressure granulation method. The granulation process was carried out in plate granulator, according to the three-level experiment plan. A mixture of raw materials prepared in a Polish factory of agrochemicals for agriculture and horticulture was used as a study material and water was used as a wetting liquid. Granulator design parameters and process parameters were treated as entrance sizes of the experiment. Three different angles of granulation blade were used in experiments. This paper presents: the results of study of equivalent diameter size and the impact of changes in the angle of granulating blade on the strength of obtained granulate. Pfost apparatus and a set of sieves used in granulometric sieve were utilized in this study. A relation was suggested P∞ = f(α, ϰ, n, ww, t). The results were presented in the form of graphs and tables. Conclusions were presented.
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Denisov, Vyacheslav A., Aleksandr Yu Kostyukov i Roman N. Zadorozhniy. "Restoration of cylinder liners for automotive tractors engines in modern conditions". Tekhnicheskiy servis mashin, nr 2 (10.06.2020): 122–33. http://dx.doi.org/10.22314/2618-8287-2020-58-1-122-133.
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One of the most promising technologies for restoring machine parts and cylinder liners is electric spark treatment as the most versatile technology that provides high-quality restoration of worn parts with wear up to 0.5 mm. (Research purpose) The research purpose is in developing a technology for restoring various cylinder liners by means of electric spark processing, selecting optimal modes and electrode materials that allow improving the quality of repair and increasing the post-repair life of the sleeve. (Materials and methods) It was taken into account when conducting research aimed at restoring the geometric parameters of the sleeve, that the coating must have sufficient adhesion strength to the surface of the sleeve under mechanical, thermal loads and long-term operation. Laboratory studies of the adhesion strength of electric spark coatings on the separation (adhesive) and on the cut, as well as tribotechnical studies of interfaces were conducted. Authors have found by analyzing the results of operational tests of restored and new cylinder liners the prospects for using electric spark treatment of worn parts, including diesel engine liners. (Results and discussion) It was shown by laboratory studies of the adhesion strength of electric spark coatings with a 0.2 mm thick BrMKc 3-1 electrode to the working surface of cylinder liners that their separation strength (adhesive) was 20-40 megapascals, and the shear strength (cohesive) was 50-80 megapascals. It was found that this provides the required functional strength of coatings with maximum operational load. The article presents the results of comprehensive research in graphs and tables. (Conclusions) The research conducted in the CCP "Nano-Center" of the FSAC VIM and operational tests in the 2nd bus fleet of Moscow confirmed the principal possibility of effectively restoring cast iron liners (blocks) using the technology of electric spark processing.
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Alkaltham, Nora S., Reem A. Aldhafiri, Ahmad M. Al-Thobity, Hassan Alramadan, Hussain Aljubran, Ijlal Shahrukh Ateeq, Soban Q. Khan, Sultan Akhtar i Mohammed M. Gad. "Effect of Denture Disinfectants on the Mechanical Performance of 3D-Printed Denture Base Materials". Polymers 15, nr 5 (26.02.2023): 1175. http://dx.doi.org/10.3390/polym15051175.
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Denture care and maintenance are necessary for both denture longevity and underlying tissue health. However, the effects of disinfectants on the strength of 3D-printed denture base resins are unclear. Herein, distilled water (DW), effervescent tablet, and sodium hypochlorite (NaOCl) immersion solutions were used to investigate the flexural properties and hardness of two 3D-printed resins (NextDent and FormLabs) compared with a heat-polymerized resin. The flexural strength and elastic modulus were investigated using the three-point bending test and Vickers hardness test before (baseline) immersion and 180 days after immersion. The data were analyzed using ANOVA and Tukey’s post hoc test (α = 0.05), and further verified by using electron microscopy and infrared spectroscopy. The flexural strength of all the materials decreased after solution immersion (p < 0.001). The effervescent tablet and NaOCl immersion reduced the flexural strength (p < 0.001), with the lowest values recorded with the NaOCl immersion. The elastic modulus did not significantly differ between the baseline and after the DW immersion (p > 0.05), but significantly decreased after the effervescent tablet and NaOCl immersion (p < 0.001). The hardness significantly decreased after immersion in all the solutions (p < 0.001). The immersion of the heat-polymerized and 3D-printed resins in the DW and disinfectant solutions decreased the flexural properties and hardness.
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Mužíková, Jitka, i Alena Kubíčková. "A study of compressibility and compactibility of directly compressible tableting materials containing tramadol hydrochloride". Acta Pharmaceutica 66, nr 3 (1.09.2016): 433–41. http://dx.doi.org/10.1515/acph-2016-0034.
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Abstract The paper evaluates and compares the compressibility and compactibility of directly compressible tableting materials for the preparation of hydrophilic gel matrix tablets containing tramadol hydrochloride and the coprocessed dry binders Prosolv® SMCC 90 and Disintequik™ MCC 25. The selected types of hypromellose are Methocel™ Premium K4M and Methocel™ Premium K100M in 30 and 50 % concentrations, the lubricant being magnesium stearate in a 1 % concentration. Compressibility is evaluated by means of the energy profile of compression process and compactibility by the tensile strength of tablets. The values of total energy of compression and plasticity were higher in the tableting materials containing Prosolv® SMCC 90 than in those containing Disintequik™ MCC 25. Tramadol slightly decreased the values of total energy of compression and plasticity. Tableting materials containing Prosolv® SMCC 90 yielded stronger tablets. Tramadol decreased the strength of tablets from both coprocessed dry binders.
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Zapater-Pereyra, M., F. van Dien, J. J. A. van Bruggen i P. N. L. Lens. "Material selection for a constructed wetroof receiving pre-treated high strength domestic wastewater". Water Science and Technology 68, nr 10 (22.10.2013): 2264–70. http://dx.doi.org/10.2166/wst.2013.483.
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A constructed wetroof (CWR) is defined in this study as the combination of a green roof and a constructed wetland: a shallow wastewater treatment system placed on the roof of a building. The foremost challenge of such CWRs, and the main aim of this investigation, is the selection of an appropriate matrix capable of assuring the required hydraulic retention time, the long-term stability and the roof load-bearing capacity. Six substrata were subjected to water dynamics and destructive tests in two testing-tables. Among all the materials tested, the substratum configuration composed of sand, light expanded clay aggregates, biodegradable polylactic acid beads together with stabilization plates and a turf mat is capable of retaining the water for approximately 3.8 days and of providing stability (stabilization plates) and an immediate protection (turf mat) to the system. Based on those results, a full-scale CWR was built, which did not show any physical deterioration after 1 year of operation. Preliminary wastewater treatment results on the full-scale CWR suggest that it can highly remove main wastewater pollutants (e.g. chemical oxygen demand, PO43−-P and NH4+-N). The results of these tests and practical design considerations of the CWR are discussed in this paper.
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Pedersen, Niels Leergaard. "Aspects of stress in optimal shaft shoulder fillet". Journal of Strain Analysis for Engineering Design 53, nr 5 (24.04.2018): 285–94. http://dx.doi.org/10.1177/0309324718763514.
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Shafts are among the most common machine elements. The typical shape used to reduce stress concentrations is circular arches due to the simplicity. A shaft is typically loaded by axial, bending, and torsional loads in different combinations. The stress concentration factors are found in tables and charts. The circular design is not optimal from a strength point of view, and the strength can be increased using shape optimization. It is in this article shown how the maximum stress from the combined loads can be minimized, when the shape is parameterized using the simple super ellipse. This makes the resulting optimized designs easily transferable to practical design. The stress evaluation is numerically performed using the finite element method using harmonic elements that facilitates an axisymmetric model although the loading is unsymmetric. The stresses are reduced by up to a factor of [Formula: see text].
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Muzikova, Jitka, Eva Snejdrova, Juraj Martiska, Bara Doubkova i Andrea Veris. "A Study of Compressibility, Compactability and Mucoadhesivity of Tableting Materials for Matrix Systems Based on Chitosan". Polymers 13, nr 21 (21.10.2021): 3636. http://dx.doi.org/10.3390/polym13213636.
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The objective of the present research is to evaluate directly compressible chitosan-based tableting materials for the formulation of mucoadhesive matrix tablets intended for targeted drug release to distal segments of the GIT. The influence of sodium alginate, hypromellose, and silicified microcrystalline cellulose (P90) on compressibility, compactability and lubricant sensitivity ratio was tested. Furthermore, the rheological properties of the hydrated surface layer of the matrix tablets and the mucoadhesion to a mucin substrate were analysed. Compressibility was evaluated using the energy profile of the compression process, compactability by means of the tensile strength of tablets, and lubricant sensitivity ratio was calculated to assess the sensitivity to lubricant. Addition of P90 to chitosan improved compressibility, which is demonstrated by the increase in the energy of plastic deformation and the higher tensile strength of tablets. P90 also significantly reduced the high lubricant sensitivity of chitosan. Presence of retarding components led to a decrease in Emax. All tested matrix tablets revealed a good mucoadhesion without a negative effect of P90 content. The viscosity of a gel layer on the surface of matrix tablets containing hypromellose was higher compared to those with sodium alginate. This was not reflected in the adhesive strength of the tablets. The formulated tableting materials combining chitosan and P90 are a suitable matrix for incorporation of an active ingredient, whose delayed release in the intestine can be achieved by the functionality of the chitosan-sodium alginate complex.
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Etzler, Frank M., Tommasina Bramante, Richard Deanne, Svetlana Sienkiewicz i F. J. Chen. "Tablet Tensile Strength: An Adhesion Science Perspective". Journal of Adhesion Science and Technology 25, nr 4-5 (styczeń 2011): 501–19. http://dx.doi.org/10.1163/016942410x525687.
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Antipas, I. R. "Effect of Glass Fiber Reinforcement on the Mechanical Properties of Polyester Composites". Advanced Engineering Research (Rostov-on-Don) 23, nr 4 (27.12.2023): 387–97. http://dx.doi.org/10.23947/2687-1653-2023-23-4-387-397.
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Introduction. Glass fibers significantly improve the quality of composite materials, make them lighter, stronger, more corrosion resistant and thermally stable. Strengths and weaknesses of specific composites are actively discussed in the scientific and applied literature. At the same time, the effect of the ratio of fibers and matrix material on the mechanical characteristics of composites has not been sufficiently investigated. The presented study is intended to fill this gap. The work is aimed at manufacturing a composite material on a polymer basis reinforced with glass fiber, and investigating the influence of weight ratios of elements on the mechanical characteristics of the composite. For the first time, a report on the comparison of the characteristics of composites (with different fiber content) to each other and to steel is published.Materials and Methods. Fiberglass and polyester were used as starting materials with the addition of a mediator to speed up the molding process. The samples were made manually and tested for tensile strength, hardness, and impact strength using standard equipment. The results were summarized in the form of tables, visualized in the form of graphs, and processed by comparative analysis.Results. The technique of creating samples and methods of their testing were described. The research showed that hardness, tensile strength and impact resistance increased with a growth in the percentage of randomly distributed fiberglass to 50% with 50% unsaturated polyester. In this case, the maximum values of tensile strength — 175.4 MPa, hardness — 38 HV and impact resistance — 1.56 J/mm2 were obtained. The inexpediency of exceeding the proportion of fiberglass by more than 50% was experimentally proven, since mechanical properties deteriorated. This was due, in particular, to the fragility of the glass, which, if the proportions were violated, was transmitted to the entire composite. In addition, with an excessively high volume of reinforcing fibers, the resin was not enough for high-quality bonding of the elements, which significantly reduced the strength of the material. Most of the mechanical characteristics of a composite made of 50% polyester and 50% fiberglass are better than those of steel.Discussion and Conclusion. It has been proved that the properties of the composite material depend significantly on the glass fiber content. The resulting composite was compared to steel. It turned out that it had better mechanical characteristics and less weight. This allows us to recommend the material for boat hulls.
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Yin, Z., F. Hannard i F. Barthelat. "Impact-resistant nacre-like transparent materials". Science 364, nr 6447 (27.06.2019): 1260–63. http://dx.doi.org/10.1126/science.aaw8988.
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Glass has outstanding optical properties, hardness, and durability, but its applications are limited by its inherent brittleness and poor impact resistance. Lamination and tempering can improve impact response but do not suppress brittleness. We propose a bioinspired laminated glass that duplicates the three-dimensional “brick-and-mortar” arrangement of nacre from mollusk shells, with periodic three-dimensional architectures and interlayers made of a transparent thermoplastic elastomer. This material reproduces the “tablet sliding mechanism,” which is key to the toughness of natural nacre but has been largely absent in synthetic nacres. Tablet sliding generates nonlinear deformations over large volumes and significantly improves toughness. This nacre-like glass is also two to three times more impact resistant than laminated glass and tempered glass while maintaining high strength and stiffness.
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Shrivastava, Dr Sunil Prasad. "Bamboo Housing - A Sustainable Housing with Low Energy and Cost Effective Solution in India". International Journal for Research in Applied Science and Engineering Technology 12, nr 5 (31.05.2024): 1948–51. http://dx.doi.org/10.22214/ijraset.2024.61977.
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Abstract: A major problem in our society is lack of affordable, economical and sustainable housing due to the rapidly increasing population in both urban as well as rural areas and the solution for this is bamboo housing. Since it is grown all over the world in both tropical as well as non tropical areas thus its easily available. Bamboo is very durable, highly sustainable, earthquake resistant material with high strength. It is naturally available and very versatile material, which is going to become a great alternative material for construction of buildings in upcoming future. Not just for building construction but it can also be used in various other products such as chair, tables, bookshelves, bedpost etc. The structural properties of bamboo like its axial tensile and axial compressive strength, hygroscopic nature, fire resistance, flexibility in design makes it ideal for construction. Bamboo is becoming most economical, renewable and fast growing construction material in future replacing other materials like bricks, concrete, steel, aluminum etc. Bamboo housing is the future of construction.
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Mascorro, Joe A., i Gerald S. Kirby. "Novel epoxy/anhydride alternatives for biological electron microscopy: Physical and performance characteristis of embed 812 and LX 112 in combination with NSA/NMA/DMAE". Proceedings, annual meeting, Electron Microscopy Society of America 47 (6.08.1989): 1000–1001. http://dx.doi.org/10.1017/s0424820100156985.
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Embedding media based upon an epoxy resin of choice and the acid anhydrides dodecenyl succinic anhydride (DDSA), nadic methyl anhydride (NMA), and catalyzed by the tertiary amine 2,4,6-Tri(dimethylaminomethyl) phenol (DMP-30) are widely used in biological electron microscopy. These media possess a viscosity character that can impair tissue infiltration, particularly if original Epon 812 is utilized as the base resin. Other resins that are considerably less viscous than Epon 812 now are available as replacements. Likewise, nonenyl succinic anhydride (NSA) and dimethylaminoethanol (DMAE) are more fluid than their counterparts DDSA and DMP- 30 commonly used in earlier formulations. This work utilizes novel epoxy and anhydride combinations in order to produce embedding media with desirable flow rate and viscosity parameters that, in turn, would allow the medium to optimally infiltrate tissues. Specifically, embeding media based on EmBed 812 or LX 112 with NSA (in place of DDSA) and DMAE (replacing DMP-30), with NMA remaining constant, are formulated and offered as alternatives for routine biological work.Individual epoxy resins (Table I) or complete embedding media (Tables II-III) were tested for flow rate and viscosity. The novel media were further examined for their ability to infilftrate tissues, polymerize, sectioning and staining character, as well as strength and stability to the electron beam and column vacuum. For physical comparisons, a volume (9 ml) of either resin or media was aspirated into a capillary viscocimeter oriented vertically. The material was then allowed to flow out freely under the influence of gravity and the flow time necessary for the volume to exit was recored (Col B,C; Tables). In addition, the volume flow rate (ml flowing/second; Col D, Tables) was measured. Viscosity (n) could then be determined by using the Hagen-Poiseville relation for laminar flow, n = c.p/Q, where c = a geometric constant from an instrument calibration with water, p = mass density, and Q = volume flow rate. Mass weight and density of the materials were determined as well (Col F,G; Tables). Infiltration schedules utilized were short (1/2 hr 1:1, 3 hrs full resin), intermediate (1/2 hr 1:1, 6 hrs full resin) , or long (1/2 hr 1:1, 6 hrs full resin) in total time. Polymerization schedules ranging from 15 hrs (overnight) through 24, 36, or 48 hrs were tested. Sections demonstrating gold interference colors were collected on unsupported 200- 300 mesh grids and stained sequentially with uranyl acetate and lead citrate.
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Perez-Roman, Ines, Filip Kiekens, Damian Cordoba-Diaz, Juan Jose Garcia-Rodriguez i Manuel Cordoba-Diaz. "Development of a Solid Formulation Containing a Microemulsion of a Novel Artemisia Extract with Nematocidal Activity for Oral Administration". Pharmaceutics 12, nr 9 (14.09.2020): 873. http://dx.doi.org/10.3390/pharmaceutics12090873.
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Background: Intestinal nematode infections are usually treated with benzimidazole drugs, but the emergence of resistance to these drugs has led to an increasing demand of new anthelmintic strategies. A new microemulsion formulation (ME) consisting of an Artemisia absinthium extract with proven nematocidal efficacy was previously developed. The aim of our study is to implement a D-optimal mixture design methodology to increase the amount of a silica material (loaded with this ME) in a tablet formulation, considering its tensile strength and disintegration time. Methods: 16 experiments or combinations of the 6 tablet components (loaded silica, microcrystalline cellulose, polyvinylpyrrolidone, croscarmellose, Syloid® 244 FP and magnesium stearate) were assessed. Tensile strength and disintegration time models were developed, and an optimization process was carried out. Results: Tensile strength was improved by increasing the polyvinylpyrrolidone content, while croscarmellose decreased the disintegration time. The optimized powder mixture contains 49.7% w/w of the loaded silica material. A compression force of 12 kN was applied to the powder mixture to form tablets with a tensile strength of 2.0 MPa and a disintegration time of 3.8 min. Conclusions: Our results show that D-optimal mixture designs provide a promising approach to formulate liquid-loaded silica materials.
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Sari, April Lianita, i Rusiyanto Rusiyanto. "Pengaruh Thermal Shock Resistence dan Komposisi Bahan Refraktori Terhadap Kekuatan Impact dan Struktur Makro". Jurnal Dinamika Vokasional Teknik Mesin 4, nr 2 (30.09.2019): 105–10. http://dx.doi.org/10.21831/dinamika.v4i2.27392.
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The purpose of this research is to study the effect of thermal shock and the composition of refractory materials on impact strength and macrostructure. The research methods are an experimental method. The independent variables in this research are thermal shock temperatures and the composition of refractory materials (a portion of alumina, rice husk ash and kaolin). The dependent variables in this research are impact strength and macrostructure. The data of this research is analyzed using descriptive statistic. The results are presented in tables, charts and images. The result shows that the highest value of average impact strength is 0,009560 J/mm2 with 300 °C temperature of thermal shock (∆T). The result of the macrostructure is a brittle structure with flat and shiny surface characteristics.Tujuan dari penelitian ini adalah mengetahui pengaruh thermal shock dan komposisi bahan refraktori terhadap kekuatan impact dan struktur makro. Metode yang digunakan pada penelitian ini merupakan metode eksperimen. Variabel bebas yang digunakan dalam penelitian ini yaitu variasi suhu thermal shock dan variasi komposisi bahan refraktori (alumina, abu sekam padi dan kaolin). variabel terikat yang digunakan dalam penelitian ini yaitu kekuatan impact dan struktur makro. Teknik analisis data yang digunakan adalah analisis deskriptif. data hasil penelitian disajikan dalam bentuk tabel, grafik dan gambar. Hasil penelitian menunjukkan bahwa rata-rata kekuatan impact tertinggi sebesar 0,009560 J/mm2 diperoleh pada komposisi 5 tanpa perlakuan thermal shock dan terendah sebesar 0,004049 J/mm2 dengan variasi suhu thermal shock (∆T) 300 oC dan hasil foto makro menunjukkan patahan getas dengan ciri-ciri permukaan patahan yang datar dan terlihat mengkilap
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Baro Tijerina, Manuel, Manuel Román Piña Monarrez i Jesús Barraza Contrera. "Weibull strength distribution and reliability S-N percentiles for tensile tests". REVISTA DE CIENCIAS TECNOLÓGICAS 5, nr 3 (22.09.2022): 284–99. http://dx.doi.org/10.37636/recit.v53284299.
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Based on the true stress, the ultimate material’s strength, and the fatigue slope b values, the probabilistic percentiles of the S-N curve of ductile materials are formulated. The Weibull β and η parameters used to determine the product’s reliability are determined directly from the material’s strength values corresponding to 103 and 106 cycles. And since in Table corresponding to the properties of this A538 A (b) steel and collected by table 23-A of Shigley Mechanical Engineering Design book; authors present the σt, Sut, and b values of several materials, then the Weibull parameters for each one of these materials as well as the 95% and 5% reliability percentiles of their S-N curves are given. A step-by-step application to the steel A538 A (b) material is presented. And based on the maximum and minimum applied stress values, the corresponding Weibull stress distribution was fitted and used with the Weibull strength distribution, in the stress/strength reliability function to determine the element’s reliability.
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Zirakashvili, Natela. "Applied Systems Theory: Mathematical and Numerical Simulation of Strength of Thick-wall Pipe by Using Static Elastic Problems". International Journal of Circuits, Systems and Signal Processing 15 (6.09.2021): 1346–64. http://dx.doi.org/10.46300/9106.2021.15.145.
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In Systems Theory, the Mathematical and numerical simulation of strength of thick-wall pipe by using static elastic problems is an important problem and has attracted the attention of many researches, academicians and practitioners. the The present work studies the change in the strength of a quite long isotropic thick-wall pipe (circular cylinder) for the varying pipe diameter, wall thickness and material. The pipe is in the plane deformed state, i.e. plane deformation is considered. Based on the problems of statics of the theory of elasticity, a mathematical model to calculate the strength of the thick-wall pipe was developed and the problems of statics of the theory of elasticity were set and solved analytically in the polar coordinate system. The analytical solution was obtained by the method of separation of variables, which is presented by two harmonious functions. The dependence of the pipe strength on the thickness and material of the pipe wall, when (a) normal stress is applied to the internal boundary (internal pressure) and external boundary is free from stresses and (b) normal stress is applied to the external boundary (external pressure) and the internal boundary is free from stresses, is studied. In particular, the minimum thicknesses of the walls of homogeneous isotropic circular cylinders of different materials and diameters with a plane deformed mode when the pressures in the cylinders do not exceed the admissible values were identified. Some numerical results are presented as tables, graphs and relevant consideration.
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Y Priyanka,, V. Venkatadurga Raju and V. Bhargavi. "Study on Pervious Concrete by Partial Replacement of Silica Fume and GGBS with Cement and Addition of Glass Fibers". International Journal for Modern Trends in Science and Technology, nr 8 (7.08.2020): 66–71. http://dx.doi.org/10.46501/ijmtst060813.
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Pervious Concrete for the pavements proves to be an effective and along- term solution for the universal problem of abnormal decrease of ground water table. Pervious Concrete has a unique mix design and giving special properties to the concrete which makes the concrete porous , allowing water from precipitation and other sources to pass directly through , there by reducing run off volume and increasing ground water table. Inorder to reduce the damage being caused to the environment by the use of cement , inpervious concrete , cement is replaced with pozzolanic materials such as GGBS , silica fume sand to increase strength and durability , glass fibers in stipulated ratio are added to the concrete mixture. In this study ,the mix designs such as M30 and PC30 are considered . The fine aggregate is replaced with coarseaggregate by different ratios like 0% , 5% , 10% ,15%. by adding different pozzolanic matrals like GGBS, silicafume with glassfibers. To find the effectiveness of the use of pozzolancic and glassfibes, compressive strength conducted. The following Conclusions can be summarized by analyzing tests performed on PC specimens. A significant reduction of workability. And A progressive addition in compressive strength by increasing the percentage of fine aggregates and pozzolanic materials in mix. The conclusion of fine aggregate content in the specimen increases the density and increase the pozzolanic materials addition. And addition of silica fume and GGBS in the mixtures improve strength , compressive strength increases even after adding pozzolanic materials. Due to increase of fine aggregate content. For all replacement levels of PC with other mixes goes on decreasing in strength when compared with parent grade ofM30. While comparing with PC with Pozzolanic materials, For 7 days there is a drastic change for same replacement, and for 28 days itshowssimilar trend for 25% pozzolanic concrete and goes on decreasing for strength for compressive strength. For all replacement levels of PC with pozzolanic goes on decreasing in strength when compared with parent grade of M30. Compressive strength slightly increased by adding glass fibers to the allmixes.