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1
Wei, Hu, Hu Minggang e He Qun. "Quasi-static testing of composite masonry construction". Building Research & Information 27, n. 2 (marzo 1999): 120–23. http://dx.doi.org/10.1080/096132199369589.
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Lusiak, Tomasz, Andrej Novák, Michal Janovec e Martin Bugaj. "Measuring and Testing Composite Materials Used in Aircraft Construction". Key Engineering Materials 904 (22 novembre 2021): 161–66. http://dx.doi.org/10.4028/www.scientific.net/kem.904.161.
Testo completoAbstract (sommario):
This paper is focused on the use of special composite materials for the construction of aircraft components. It focuses on measuring and testing the strength of reinforced composite materials used in damaged aircraft parts repairs. To determine the layer required to repair a part of the aircraft, it is necessary to know the strength limit of the material and its parts. The article describes experimental measurements of manufactured composite samples that have been subjected to tensile stress. Aim of the performed tensile tests was to determine the maximum tensile stress that the composite materials are able to transmit until they are damaged. Measurement determining the maximum stress level is important to ensure the required safety of the aircraft structure on which the composite structure was repaired.
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BAIER, Andrzej, e Sławomir ŻÓŁKIEWSKI. "GRINDING TESTING OF COMPOSITE MATERIALS". Scientific Journal of the Military University of Land Forces 159, n. 1 (3 gennaio 2011): 21–36. http://dx.doi.org/10.5604/01.3001.0002.2852.
Testo completoAbstract (sommario):
Grinding testing is one of the most important tests of materials applied for contact with other elements. The subject matter is limited to grinding testing and this is only the beginning of complex testing of composite materials. In this article, the tested composite materials are epoxide and polyester laminates. The selected materials can be put into use in the wagon sides construction. This article includes a proposal for a laboratory stand for comparative grinding testing and presents sample test results.
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Sosa, Edward D., Erica S. Worthy e Thomas K. Darlington. "Microwave Assisted Manufacturing and Repair of Carbon Reinforced Nanocomposites". Journal of Composites 2016 (13 ottobre 2016): 1–9. http://dx.doi.org/10.1155/2016/7058649.
Testo completoAbstract (sommario):
We report a composite capable of advanced manufacturing and damage repair. Microwave energy is used to induce thermal reversible polymerization of the matrix allowing for microwave assisted composite welding and repair. Composites can be bonded together in just a few minutes through microwave welding. Lap shear testing demonstrates that microwave welded composites exhibit 40% bond strength relative to composites bonded with epoxy resin. Double cantilever beam testing shows 60% recovery in delamination strength after microwave assisted composite repair. The interfacial adhesion and composite repair after microwave exposure are examined by X-ray computed tomography. The microwave processing is shown to be reproducible and consistent. The ability to perform scalable manufacturing is demonstrated by the construction of a large structure from smaller components.
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Gong, Xiaozhou, Pengying Pei, Yu Hu e Xiaogang Chen. "Experimental investigation of low velocity impact on textile cellular composite with different energy construction". Journal of Industrial Textiles 48, n. 6 (22 gennaio 2018): 1009–23. http://dx.doi.org/10.1177/1528083718754900.
Testo completoAbstract (sommario):
Cellular composite, with an array of regular hexagonal cells in the cross section, is a type of textile composites having the advantage of being light weight and energy absorbent over the solid composite materials. However, when it is under the same energy level of low velocity impact with different tup mass and velocity, its behavior is yet unknown. In the experiment, four groups of samples, with twelve geometrical variants have been systematically created for the impact testing. The impact test is running in two categories with one type of low velocity impact with initial velocity of 5.5 m/s by the tup mass of 0.55 kg, and another testing under the similar impact energy but with a lower initial velocity around 2.0 m/s with heavier tup mass of 4.52 kg. The impact energies in the above cases are very similar about 8.5 J, which indicates that the impact energy is the same while the energy construction is different. After the test, it is found that composite with medium cell size has more stable mechanical performances under various exposed impact conditions. It is also concluded that composites with big cell size are much easier to be destroyed under heavier impact tup, therefore, under condition of more critical loading force, it is necessary to find a way to enhance the big cell sized composites’ wall material in order to strengthen their structure performances. The results of this work provide a reference for the researchers who are kneeing to investigate the impact mechanism of textile cellular composites.
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Xiang, Zhenglong, Hongrun Wu e Fei Yu. "A Genetic Algorithm-Based Approach for Composite Metamorphic Relations Construction". Information 10, n. 12 (10 dicembre 2019): 392. http://dx.doi.org/10.3390/info10120392.
Testo completoAbstract (sommario):
The test oracle problem exists widely in modern complex software testing, and metamorphic testing (MT) has become a promising testing technique to alleviate this problem. The inference of efficient metamorphic relations (MRs) is the core problem of metamorphic testing. Studies have proven that the combination of simple metamorphic relations can construct more efficient metamorphic relations. In most previous studies, metamorphic relations have been mainly manually inferred by experts with professional knowledge, which is an inefficient technique and hinders the application. In this paper, a genetic algorithm-based approach is proposed to construct composite metamorphic relations automatically for the program to be tested. We use a set of relation sequences to represent a particular class of MRs and turn the problem of inferring composite MRs into a problem of searching for suitable sequences. We then dynamically implement multiple executions of the program and use a genetic algorithm to search for the optimal set of relation sequences. We conducted empirical studies to evaluate our approach using scientific functions in the GNU scientific library (abbreviated as GSL). From the empirical results, our approach can automatically infer high-quality composite MRs, on average, five times more than basic MRs. More importantly, the inferred composite MRs can increase the fault detection capabilities by at least 30 % more than the original metamorphic relations.
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Jutila, Aarne, Risto Mäkipuro e Lauri Salokangas. "Testing a Wood-Concrete Composite Bridge". Structural Engineering International 7, n. 4 (novembre 1997): 275–77. http://dx.doi.org/10.2749/101686697780494635.
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Geringer, J. W., Y. Katoh, S. Gonczy, T. Burchell, M. Mitchell, M. Jenkins e W. Windes. "ASME Code Rules and ASTM Standards Integration for Ceramic Composite Core Materials and Components1". Journal of Physics: Conference Series 2048, n. 1 (1 ottobre 2021): 012020. http://dx.doi.org/10.1088/1742-6596/2048/1/012020.
Testo completoAbstract (sommario):
Abstract Fiber-reinforced ceramic matrix composites have many desirable properties for high-temperature nuclear applications, including excellent thermal and mechanical properties and reasonable to outstanding radiation resistance. Over the last 20 years, the use of ceramic composite materials has already expanded in many commercial nonnuclear industries as fabrication and application technologies mature. The new ASME design and construction rules under Section III, Subsection HH, Subpart B lay out the requirements and criteria for materials, design, machining and installation, inspection, examination, testing, and the marking procedure for ceramic composite core components, which is similar to the established graphite code under Section III, Subsection HH, Subpart A. Moreover, the general requirements listed in Section III, Subsection HA, Subpart B are also expanded to include ceramic composite materials. The code rules rely heavily on the development and publication of standards for composite specification, classification, and testing of mechanical, thermal, and other properties. These test methods are developed in the American Society for Testing and Materials Committee C28 on Advanced Ceramics with a current focus on ceramic composite tubes. Details of the composites code, design methodology, and similarities to the graphite code, as well as guidance for the development of specifications for ceramic composites for nuclear application and recent standard developments, are discussed. The next step is to “close the gap” to support licensing aspects by validating the code with benchmarking data.
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Gillespie, J. W., D. A. Eckel, W. M. Edberg, S. A. Sabol, D. R. Mertz, M. J. Chajes, H. W. Shenton et al. "Bridge 1-351 over Muddy Run: Design, Testing, and Erection of an All-Composite Bridge". Transportation Research Record: Journal of the Transportation Research Board 1696, n. 1 (gennaio 2000): 118–23. http://dx.doi.org/10.3141/1696-52.
Testo completoAbstract (sommario):
Bridge 1.351 on Business Route 896 in Glasgow, Delaware, was replaced with one of the first state-owned all-composite bridges in the nation. Composites are lightweight construction materials that do not corrode, which results in benefits such as ease of construction and reduced maintenance costs. A summary of the design, large-scale testing, fabrication, erection, and monitoring of this bridge is presented. The bridge was designed to AASHTO load and resistance factor design specifications. A methodology was developed to incorporate the engineering properties of these unique composite materials into the design. The bridge consists of two 13 × 32 ft (3.96 × 9.75 m) sections joined by a unique longitudinal joint. The sections have sandwich construction consisting of a core [28 in. (71.12 cm) deep] and facesheets [0.4 to 0.6 in. (10.16 to 15.24 mm) thick] that provide shear and flexural rigidity, respectively. The composite bridge was fabricated with E-glass preforms and vinyl-ester resin, which offers excellent structural performance and long-term durability. Each of the sections was fabricated to near-net shape in a single step by a vacuum-assisted resin transfer molding process. The overall structural behavior has been accurately predicted with simple design equations based on sandwich theory for anisotropic materials. Large-scale testing of full-sized subcomponents was conducted to prove that the design satisfied deflection, fatigue, and strength limit states. A redundant longitudinal joint was designed that consisted of both an adhesively bonded vertical joint between sections and splice plates. Assembly procedures were developed, and transverse testing of the full-sized joint was conducted. Final bridge sections were proof-tested to the strength limit state. The construction phase included section positioning, joint assembly, and application of a latex-modified concrete wear surface. The bridge was reopened to traffic on November 20, 1998. Results from the long-term monitoring effort will be documented.
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Bosák, Lukáš, e Milan Palko. "Wall Panel Made of Bio-composites". MATEC Web of Conferences 279 (2019): 02010. http://dx.doi.org/10.1051/matecconf/201927902010.
Testo completoAbstract (sommario):
Sustainability is currently an important part of the building industry. The development of new building constructions and the use of ecological materials is a very popular topic in this area. One example of organic material are natural fibres bio-composites. Bio-composite materials are currently used in the form of laminates mainly used in the sport and furniture industries. This article addresses their use in the building industry as the outer envelope of buildings. The article deals with the testing of the influence of UV radiation and moisture on the degradation of Bio-composites with recommendation of possible ways of their protection. In the next section, it deals with the design of composite wall panel with Bio-composite laminates on the top layer. This panel will contain mycelium as thermal insulation. The assumption of the use of this type of construction in the building industry is based on the possibility of replacing conventional materials used nowadays and reducing the environmental load by the building industry. The use of new types of eco-friendly building materials is in accordance with the EU strategy.
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Ahmad, Hilton, e Khairi Supar. "Experimental Strength of Woven Fabric Kenaf Composite Plates with Different Stacking Sequences". Applied Mechanics and Materials 833 (aprile 2016): 27–32. http://dx.doi.org/10.4028/www.scientific.net/amm.833.27.
Testo completoAbstract (sommario):
Awareness on implementing sustainable construction materials has risen significantly leading to increased renewable materials used commercially. Kenaf fibers are potentially used as composite reinforcements and combined with epoxy polymer to produce an advanced engineering material that may offer superior specific stiffness (and strength) to its density. Other advantages include renewability, easy during fabrication handling stage and relatively cheaper than commercial fibers counterparts. Current project aims to investigate mechanical strength of woven fabric kenaf composites coupons with different stacking orientations. Testing series under investigation includes different lay-up types with variation of plate thickness. Mechanical testing is conducted referred to relevant code of practice and associated damage observations during testing will be recorded. It is suggested that these materials are potential to provide an alternative reinforcing materials in composite fabrications and enhanced its applicability to a greater extent in local sector.
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Lindner, Marco, Konrad Vanselow, Sandra Gelbrich e Lothar Kroll. "Fibre-reinforced polymer stirrup for reinforcing concrete structures". Technologies for Lightweight Structures (TLS) 3, n. 1 (24 gennaio 2020): 17–24. http://dx.doi.org/10.21935/tls.v3i1.117.
Testo completoAbstract (sommario):
Fibre-plastic composites offer an interesting alternative to concrete reinforcement. In order to expandthe application spectrum of reinforcing elements in fibre composite construction, a new steel-free bracingsystem with reduced radii of curvature was developed. An improvement in load carrying capacity couldbe proven in extensive investigations based on international testing methods and verified by practicaltests. With the help of newly reinforced precast concrete elements from the area of waterways and trafficroutes, a high potential for lightweight construction and resource efficiency can be impressivelydemonstrated.
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Bakht, Baidar, e Ray Krisciunas. "Testing a Prototype Steel-Wood Composite Bridge". Structural Engineering International 7, n. 1 (febbraio 1997): 35–41. http://dx.doi.org/10.2749/101686697780495391.
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Weiler, Lia, e Anya Vollpracht. "Environmental Compatibility of Carbon Reinforced Concrete: Irrigated Construction Elements". Key Engineering Materials 809 (giugno 2019): 314–19. http://dx.doi.org/10.4028/www.scientific.net/kem.809.314.
Testo completoAbstract (sommario):
To foster a sustainable deployment of the innovative composite material ‘carbon concrete composite’ in the building sector, it is necessary to ensure its resource efficiency and environmental compatibility. The Institute for Building Materials Research of the RWTH Aachen University is therefore investigating the leaching behavior of this material, especially for the case of irrigated façade elements. Laboratory and outdoor exposure tests are run to determine and assess the heavy metal and trace element emissions by leaching. Feasible interconnections between laboratory and outdoor examinations can be used to develop a faster testing of future composite materials. Current results show no critical release of environmental harmful substances from carbon concrete composite.
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LINDE, PETER. "VIRTUAL TESTING OF STIFFENED COMPOSITE PANELS AT AIRBUS". International Journal of Structural Stability and Dynamics 10, n. 04 (ottobre 2010): 589–600. http://dx.doi.org/10.1142/s0219455410003634.
Testo completoAbstract (sommario):
The steady increase of composite parts in civil aircraft over the last three decades has recently been followed by a radical increase of weight percentage composites in the structure. In the most recent long range aircraft under development by both Boeing and Airbus, most major structure components, not only of the wings but also of the fuselage, now consist of composites. This necessitates an increased use of efficient structural simulation capabilities. One important aspect of this is the virtual testing of shear compression panels at Airbus, which will be presented here. Having served well for Glare during the A380 development, it is currently undergoing considerable development to extend its capacity to composites. Summarized under the designation "Simulation of Panels in AirCraft", (SIMULPAC), this platform is here introduced and described in terms of functioning and methodology. It has played a major role in the initial A350 developments: in the first designs, during virtual testing of the configuration of new components and for predictions of the first real shear compression panels.
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Gouasmi, M. T., A. S. Benosman, Hamed Taïbi, N. Kazi Tani e Mohammed Belbachir. "Destructive and Non-Destructive Testing of an Industrial Screed Mortar Made with Lightweight Composite Aggregates WPLA". International Journal of Engineering Research in Africa 33 (novembre 2017): 140–58. http://dx.doi.org/10.4028/www.scientific.net/jera.33.140.
Testo completoAbstract (sommario):
Today, only a very small portion of plastic waste is recycled, while huge quantities remain untreated and are becoming increasingly worrying. The search for other alternatives is still an urgent necessity so that these wastes can be reduced to the maximum; their valorization may be the best solution. This study concerns a new technique for the valorization of polyethylene terephthalate (PET) plastic bottle wastes, in order to design a composite material, i.e. siliceous sand-PET, which then gives a Waste Plastic Lightweight Aggregate “WPLA”. Our hope is to provide solutions to specific and general applications in the field of construction. Some observations are noted on the effects of this composite on destructive and non-destructive testing, such as the physical properties and mechanical behaviors of an industrial composite screed, by substituting 0, 25, 50, 75 and 100% by weight of natural aggregate by this composite. Scanning electron microscope (SEM), FT-IR and X-ray diffraction analyses were used to better understand the cement hydration products of the composite mortars. Some possible uses of this screed, or even of the composite itself, can subsequently be recommended. Encouraging results were obtained regarding the usage of this composite aggregate as an eco-material in the field of construction for sustainable development. In addition, it provides environmental-friendly and cost-effective solutions in using recycled materials for concrete construction applications.
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Javadian, Alireza, Hortense Le Ferrand, Dirk E. Hebel e Nazanin Saeidi. "Application of Mycelium-Bound Composite Materials in Construction Industry: A Short Review". SOJ Materials Science & Engineering 7, n. 2 (22 ottobre 2020): 1–9. http://dx.doi.org/10.15226/sojmse.2020.00162.
Testo completoAbstract (sommario):
Mycelium-bound composite materials are a new class of sustainable and affordable biocomposites that have been recently introduced into packaging, fashion, and architecture as alternative to traditional synthetic materials. In recent years extensive investigation and research studies have been dedicated to explore methods of production and processing as well as to find potential applications for mycelium-bound composite materials. However, application of this novel biocomposite within the construction industry has been limited to only small-scale prototypes and exhibition installations. The problems with low mechanical properties, high water absorption and lack of standard methods for production and testing of mycelium-bound composite materials remain as main challenges that need to be addressed when used as non-structural or semi-structural elements. This short review aims to display the potential of mycelium-bound composite materials for their use within the construction sector in the form of thermal and acoustic insulation as well as replacement for drywalls and tiles. This review summarizes the main available information with regards to the properties of mycelium-bound composites that have been used in construction sector while suggesting the direction for the future research and development on these biocomposites for their applications within the construction industry.
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Ji, Shunhui, Liming Hu, Yihan Cao, Pengcheng Zhang e Jerry Gao. "Verifiable Model Construction for Business Processes". International Journal of Software Engineering and Knowledge Engineering 31, n. 07 (luglio 2021): 1017–42. http://dx.doi.org/10.1142/s0218194021500315.
Testo completoAbstract (sommario):
Business process specified in Business Process Execution Language (BPEL), which integrates existing services to develop composite service for offering more complicated function, is error-prone. Verification and testing are necessary to ensure the correctness of business processes. SPIN, for which the input language is PROcess MEta-LAnguage (Promela), is one of the most popular tools for detecting software defects and can be used both in verification and testing. In this paper, an automatic approach is proposed to construct the verifiable model for BPEL-based business process with Promela language. Business process is translated to an intermediate two-level representation, in which eXtended Control Flow Graph (XCFG) describes the behavior of BPEL process in the first level and Web Service Description Models (WSDM) depict the interface information of composite service and partner services in the second level. With XCFG of BPEL process, XCFGs for partner services are generated to describe their behavior. Promela model is constructed by defining data types based on WSDM and defining channels, variables and processes based on XCFGs. The constructed Promela model is closed, containing not only the BPEL process but also its execution environment. Case study shows that the proposed approach is effective.
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Woytowich, David L., Martin W. King, Myron G. Britton e Jan A. Oleszkiewicz. "Accelerated testing of a filled polyester E-glass composite in acidic environments". Canadian Journal of Civil Engineering 18, n. 5 (1 ottobre 1991): 799–809. http://dx.doi.org/10.1139/l91-097.
Testo completoAbstract (sommario):
This paper describes the results of an accelerated laboratory investigation to measure the rate of deterioration of a newly developed filled plastic composite exposed to acidic (sewage) environments. The specific objective was to compare the relative rates of deterioration of an experimental filled filament wound (FFW) polyester composite immersed in sulfuric (pH 2.23) and acetic (pH 2.22) acid environments at 45 °C. Deterioration was measured in terms of changes in wet specimen weight, loss in dried (soluble) material weight and mechanical properties, the extent of chemical dissolution, and the depth of penetration. Based on regression analyses of these parameters, it was found that the rate of deterioration was a function of the square root of immersion time. Deterioration of the FFW composite in acetic acid was 1.6–3.9 times greater than in the sulfuric acid environment. The loss in wet flexural properties and the dissolution behavior of aluminum trihydrate were not influenced by the type of acid environment. Based on the findings of this study, sulfuric acid is recommended as a standard laboratory test medium for fiberglass reinforced plastic composites used in construction of sewage facilities and pipelines where deterioration due to sulfur oxidizing bacteria is anticipated. Key words: accelerated, polyester, fillers, filament-wound, environment, acidic, durability, composite, septic tanks.
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Morăraș, Ciprian, Catalin Andrei Tugui, Rozina Steigmann, Paul Doru Barsanescu, Bogdan Leitoiu e Viorel Goanta. "Mechanical Testing of GFRP Composite Materials Used in Wind Turbine Blades Construction". Advanced Materials Research 1157 (febbraio 2020): 142–48. http://dx.doi.org/10.4028/www.scientific.net/amr.1157.142.
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The paper proposes to present the results of the evaluation of glass fiber reinforced plastics (GFRP) used in the construction of wind turbine blades. In a wind turbine, the blades are the most exposed to damages and the defects which appear are various and are connected with the type of manufacture, simple/complex loading, environmental conditions etc. In order to increase the lifetime span and to analyze the degradation phenomena during the materials functioning, destructive evaluation tests are performed to determine the mechanical property, by testing pure shear on specimens Iosipescu, from GFRP with woven reinforcement at [± 45°] and [0°/90°], with the shear fixture, endowment of Technical University Gh.Asachi Iasi.
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Oravec, Pavel, e Michal Hamala. "Acoustic Qualities of a Composite Timber - Concrete Ceiling Construction". Advanced Materials Research 649 (gennaio 2013): 273–76. http://dx.doi.org/10.4028/www.scientific.net/amr.649.273.
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This paper describes a modern composite timber - concrete ceiling construction. It also compares and evaluates the acoustic qualities (sound insulation and a level of acoustic pressure of impact sound), which were measured on a sample of a 3 x 3.6 m size in the experimental measurements in the acoustics testing laboratory certified by CSI Zlin. In the first case, the construction is evaluated as a supporting ceiling panel without any additional layers. In the second and third option it is evaluated as a ceiling construction with structural modifications (a supporting ceiling with some floor layers of different combinations).
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Popov, A. V., V. Yu Voloshina, K. A. Zhuravsky e M. A. Labina. "Acoustic Emission Method of Diagnostics of Structures Made of Composite Materials Based on Invariants". Advanced Engineering Research 22, n. 4 (9 gennaio 2004): 331–37. http://dx.doi.org/10.23947/2687-1653-2022-22-4-331-337.
Testo completoAbstract (sommario):
Introduction. Composite materials are the main way to reduce the weight of the aircraft structure and improve its flight performance. Methods of non-destructive testing enable to assess the technical condition of composite materials, as well as to determine stress concentrators in them to make a decision on the further operation of this control object. The paper presents an analysis of the use of composite materials in the aircraft design and ways to improve their flight performance through the application of composites. An acoustic-emission method for assessing crack resistance based on invariants was described. The study aimed at increasing the accuracy and efficiency of assessing the crack resistance of aircraft structures made of composite materials through the use of the acoustic emission method of non-destructive testing. Materials and Methods. The nomenclature of composite materials used in aircraft was given, and their physical and mechanical properties were compared. The acoustic emission method of non-destructive testing of composite materials based on invariant ratios was used. Results. A method for assessing the crack resistance of primary structural elements based on the invariants of acoustic emission processes, and a program apparatus complex based on it has been developed. Discussion and Conclusions. The results obtained can be used to determine the strength characteristics of composite materials by the acoustic emission method of non-destructive testing to assess the technical condition of primary structural elements in mechanical engineering, shipbuilding, and aircraft construction. The paper is recommended to researchers involved in the development of aircraft.
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ABRAMOV, I. V., Yu V. TURYGIN, P. V. LEKOMTSEV, A. V. ROMANOV, A. V. BUCHKIN e Z. S. SAIDOVA. "Some Results of Testing Anchoring Devices Used in Composite Reinforcement Tensioning". Stroitel'nye Materialy 767, n. 1-2 (2019): 64–69. http://dx.doi.org/10.31659/0585-430x-2019-767-1-2-64-69.
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Dragan, Krzysztof, e Piotr Synaszko. "In-Service Flaw Detection and Quantification in the Composite Structures of Aircraft". Fatigue of Aircraft Structures 2009, n. 1 (26 luglio 2009): 37–41. http://dx.doi.org/10.2478/v10164-010-0003-0.
Testo completoAbstract (sommario):
In-Service Flaw Detection and Quantification in the Composite Structures of Aircraft Taking into consideration the increased usage of composites for aircraft structures there is a necessity for gathering information about structural integrity of such components. During the manufacturing of composites as well as during in service and maintenance procedures there is a possibility for damage occurrence. There is a large number of failure modes which can happen in such structures. These failure modes affect structural integrity and durability. In this work modern approach for detection of composites damage detection such as: delaminations, disbonds, foreign object inclusion and core damage has been presented. This detection is possible with the use of advanced P-C aided Non Destructive Testing methods. In the article nondestructive testing results for the composite vertical tail skins on MiG-29 aircraft will be delivered as well as some results of F-16 horizontal stabilizer and W-3 helicopter main rotor blades. Moreover some results of the composite honeycomb and sandwich structures will be presented based on the materials used in the construction of gliders and small aircraft. Factors affecting structural integrity and durability of the composites will be highlighted as well as necessity of the inspection with the use of modern NDT techniques. At the end some effort with Structural Health Monitoring connected with possibility of condition monitoring of composites will be presented.
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Prabakaran, E., D. Vasanth Kumar, A. Jaganathan, P. Ashok Kumar e M. Veeerapathran. "Analysis on Fiber Reinforced Epoxy Concrete Composite for Industrial Flooring – A Review". Journal of Physics: Conference Series 2272, n. 1 (1 luglio 2022): 012026. http://dx.doi.org/10.1088/1742-6596/2272/1/012026.
Testo completoAbstract (sommario):
Abstract Fiber composites are the having an good scope in construction industry as they are light in weight, durable, economic, and resistant to temperatures. Many researchers concentrate on the composites for the industrial flooring with the fibers. The main objective of this paper is to review the fiber reinforced epoxy for industrial flooring. Epoxy can be used as flooring elements in industries as they deliver good performance. Since, natural and synthetic fibres can be used with filler matrices, which are very much cheaper than the conventional steel fibres reinforced composite concrete flooring and other type of composites here fibre is considered for reinforcing with epoxy or polymer concrete filler matrix. Fibre-polymer and fibre-concrete composite properties has been reviewed for testing procedure for flexural test, bending test, tensile test and based on the results, it is clear that the fibre-polymer concrete composite, which has good mechanical properties and performance than the mentioned composites, can be made for industrial flooring
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Rupal, Ashmita, Sivansankara Rao Meda, Abhishek Gupta, Ishan Tank, Ashish Kapoor, Sanjay Kumar Sharma, T. Sathish e P. Murugan. "Utilization of Polymer Composite for Development of Sustainable Construction Material". Advances in Materials Science and Engineering 2022 (8 giugno 2022): 1–15. http://dx.doi.org/10.1155/2022/1240738.
Testo completoAbstract (sommario):
Polymers have gained an extensive application due to their versatility of properties and benefits. Hence, the polymer blends and composites reinforced with different infusions at different scales, macro to nanofillers, can be fabricated, leading to specific tailormade applications. The main objective of this investigation is to overview the various studies carried out to reuse the waste materials like electroplating sludge, fly ash, etc. For the development of construction materials. This paper summarizes the use of polymers in composite material formulations for the development of building materials such as lightweight concrete, protective coatings, paver blocks, bricks, and structural components. Different tests, namely viscosity, density, flash point, amine value, and epoxy equivalent weight, were performed on polymers to find their suitability as binder materials. Various laboratory tests such as compressive strength, water absorption, tear resistance, flexural strength, and split tensile tests were carried out to determine the mechanical properties of the developed materials. By using polymers with the addition of sustainable filler and waste materials, the replacement of costly raw material can be achieved by more than 50% in the case of paver blocks, up to 60% in bitumen-polymer composite, 80% in case of lightweight concrete and polymer-based panels. This insight gives the framework for the selection of different materials, optimization of combining ratio of materials, and their testing for the development of polymer-based materials.
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Hosur, M. V., Jessie B. Mayo Jr., E. Wetzel e S. Jeelani. "Studies on the Fabrication and Stab Resistance Characterization of Novel Thermoplastic-Kevlar Composites". Solid State Phenomena 136 (febbraio 2008): 83–92. http://dx.doi.org/10.4028/www.scientific.net/ssp.136.83.
Testo completoAbstract (sommario):
Kevlar has demonstrated the ability to protect well against ballistic threats but has low resistance to puncture. Correctional Kevlar has shown good resistance to puncture. However, the fabric is expensive, difficult to manufacture because of its tight weave construction, and has limited protection against ballistic threats. In an effort to produce materials that are less bulky, more flexible, and resistant to puncture, thermoplastic-Kevlar (TP-Kevlar) composites have been examined. Kevlar fabric was impregnated with thermoplastic film using a hot press to produce the composites. Static and dynamic puncture resistant properties of the TP-Kevlar composites were investigated using a National Institute of Justice (NIJ Standard 0115.00) Stab Tower. The TP-films used in this study were polyethylene, Surlyn, and co extruded-Surlyn, which is a co extrusion of Surlyn and polyethylene. Response of the polyethylene (PE)-Kevlar composites, Surlyn-Kevlar composites, and co extruded (COEX)-Kevlar composites to spike and knife threats under static and dynamic conditions were compared with that of neat Kevlar. The infusion of thermoplastic films into the Kevlar fabric was shown to dramatically increase puncture resistance during quasi-static and dynamic testing with spikes. The TP-film type also made a difference when examining the resistance on a comparative basis of the TP-Kevlar targets. The TP-Kevlar composite targets showed more resistance to quasi-static spike testing than quasi-static knife testing. Weapon comparisons revealed that the TP-Kevlar composite targets had more resistance to dynamic knife testing than dynamic spike testing.
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Simanjorang, Michael Rivaldo, Heru Susanto e Muhammad Luqman Bukhori. "DESIGN AND CONSTRUCTION OF MIXER WITH VARIABLE SPEED FOR MANUFACTURING NANOPARTICLE COMPOSITE MATERIALS". Teknika STTKD: Jurnal Teknik, Elektronik, Engine 8, n. 2 (15 novembre 2022): 257–66. http://dx.doi.org/10.56521/teknika.v8i2.653.
Testo completoAbstract (sommario):
Variable speed mixer machine is a tool to help stir and mix resin with nanoparticles, design and build of the mixer plan the design of the variable speed mixer which aims to make the resin viscosity more evenly distributed in the manufacture of composites and determine the performance of the equipment produced by the variable speed mixer. This is because in manual mixing the mixed materials such as resin nanoparticles have not been mixed evenly or homogeneously. This mixer design tool can be used as a basis for developing work in the field of composite mixing, problems in composite manufacturing include; resin flow control and how to prevent the occurrence of white spots (white dots in the composite). y designing and using this variable speed mixer machine, the results of designing a mixer image with variable speed control using solid works software is the first step in working on a mixer design with variable speed control, after having data in the form of design drawings, a product design in the form of a mixer with variable speed is obtained. . speed control. It is known that the specifications of the mixer with variable speed for composites and nanoparticles are known, it is known that the working principle of a mixer with variable speed control for composites and nanoparticles can make the viscosity mixed more evenly. because the stirring speed regulated by the speed control has a constant speed. The results of testing the mixer machine with speed control, namely the motor can work according to the design plan, where the motor can produce rotation with the required variations and can be adjusted as needed.
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Szymański, Rafał. "Non-Destructive Testing of Thermoplastic Carbon Composite Structures". Transactions on Aerospace Research 2020, n. 1 (1 marzo 2020): 34–52. http://dx.doi.org/10.2478/tar-2020-0003.
Testo completoAbstract (sommario):
AbstractThe article is in line with the contemporary interests of companies from the aviation industry. It describes thermoplastic material and inspection techniques used in leading aviation companies. The subject matter of non-destructive testing currently used in aircraft inspections of composite structures is approximated and each of the methods used is briefly described. The characteristics of carbon preimpregnates in thermoplastic matrix are also presented, as well as types of thermoplastic materials and examples of their application in surface ship construction. The advantages, disadvantages and limitations for these materials are listed. The focus was put on the explanation of the ultrasonic method, which is the most commonly used method during the inspection of composite structures at the production and exploitation stage. Describing the ultrasonic method, the focus was put on echo pulse technique and the use of modern Phased Array heads. Incompatibilities most frequently occurring and detected in composite materials with thermosetting and thermoplastic matrix were listed and described. A thermoplastic flat composite panel made of carbon pre-impregnate in a high-temperature matrix (over 300°C), which was the subject of the study, was described. The results of non-destructive testing (ultrasonic method) of thermoplastic panel were presented and conclusions were drawn.
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Zhou, J., A. Pellegrino, U. Heisserer, P. W. Duke, P. T. Curtis, J. Morton, N. Petrinic e V. L. Tagarielli. "A new technique for tensile testing of engineering materials and composites at high strain rates". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 475, n. 2229 (settembre 2019): 20190310. http://dx.doi.org/10.1098/rspa.2019.0310.
Testo completoAbstract (sommario):
A new test technique and bespoke apparatus to conduct high strain rate measurements of the tensile response of materials are presented. The new test method is applicable to brittle solids and composites as well as high-performance fibres, yarns and tapes used in composite construction. In this study, the dynamic response of monolithic poly(methyl methacrylate) and unidirectional composites based on Dyneema® tape, Dyneema® SK75 yarn and Kevlar® 49 yarn are explored. The technique allows early force equilibrium and yields valid tensile stress–strain curves, which include part of the elastic material response. The new method also enables investigation of size effects in tape and yarn materials, allowing testing of specimens of arbitrary length.
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Sahmenko, Genadijs, Maris Sinka, Ugis Paurins e Diana Bajare. "Production Technology of Ecological High Performance Fibre Composite Construction Materials". Journal of Physics: Conference Series 2423, n. 1 (1 gennaio 2023): 012005. http://dx.doi.org/10.1088/1742-6596/2423/1/012005.
Testo completoAbstract (sommario):
Abstract Eco materials derived from natural plant fibres and mineral binders are an alternative solution for modern ecological construction. This research is devoted to developing production technology for ecological high-performance fibre composite materials based on hemp shives and magnesium binder. The proposed composite wall structures consist of outer envelope layers made from dense hemp composite and middle insulation layer made from a lightweight hemp composite. The article describes the process of manufacturing a hemp composite boadr and the process of creating a three-layer structure of the outer wall. Used mix compositions are based on previously elaborated mix compositions based on magnesium oxychloride cement (MOC) binder and hemp shives. This study presents the case study of testing samples from hemp composite boards produced in actual industrial conditions. During an experiment, 20% magnesium oxide was replaced as an alternative binder, such as metakaolin and fly ash. The purpose of modifying the compositions of the composite is to increase the water resistance of the material and improvement of the hydraulic properties of the material, as it was previously found that this material is hygroscopic concerning the high humidity of the ambient air.
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Durrans, Daniel, Denise Lee e Monower Sadique. "APPLICATION OF CONCRETE ENCASED ECOBRICK BLOCKS IN THE UK’S CONSTRUCTION INDUSTRY". Kufa Journal of Engineering 13, n. 4 (14 ottobre 2022): 70–89. http://dx.doi.org/10.30572/2018/kje/130406.
Testo completoAbstract (sommario):
The construction industry within the UK is at the forefront of new and alternative materials, which aid in efficient, sustainable and environmental-friendly construction projects. The concept of filling a single use plastic bottle with plastic waste and encasing it within a concrete surround, producing a composite block meets all three objectives. Due to the lack of ecobrick research within the UK, it became the catalyst for researching the concrete encased ecobrick block. At 7 day compressive testing the composite blocks were all weaker than the control samples and at 28 days the results were mixed. In comparison to a global study (Oman) the composite blocks were all greater in compressive strength. In conclusion, the composite blocks were found to be adequate for non-load bearing structural elements within the UK’s construction industry.
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Watkins, Stetson, e James Bittner. "Resonance Bond Testing: Theory and Application". Materials Evaluation 79, n. 6 (1 giugno 2021): 512–19. http://dx.doi.org/10.32548/2021.me-04225.
Testo completoAbstract (sommario):
Resonance bond testing is a nondestructive testing (NDT) technique that is used to detect disbonds, delaminations, and other voids in composite materials. The aerospace industry has seen an increase in the use of carbon fiber reinforced plastics (CFRP) for aircraft and spacecraft construction. Composite materials offer many advantages over traditional metallic structures, which include weight savings, increased strength, design for specific load paths, and the ability to easily construct geometrically complex structures. Resonance bond testing has many established uses for metallic structures as well, such as aluminum skin-to-skin and skin-to-core bonds. This bond testing technique has been around for many decades but is used by only a small portion of the NDT community. Ultrasonic testing (UT), specifically phased array ultrasonic testing (PAUT), using linear array techniques has proven to be a reliable method for the inspection of CFRP laminates. When composite structures do not permit the use of high-frequency sound waves due to rapid attenuation, resonance bond testing is a proven alternative. In this paper, the authors will discuss the theory behind resonance bond testing and how it has and continues to play an important role in the NDT industry.
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Al-Azad, Nahiyan, e Mohd Shah Mohd. Kamal. "Investigation of specific energy absorption of natural fiber honeycomb sandwich structure composite as building construction material application". IOP Conference Series: Materials Science and Engineering 1217, n. 1 (1 gennaio 2022): 012012. http://dx.doi.org/10.1088/1757-899x/1217/1/012012.
Testo completoAbstract (sommario):
Abstract The usage of incorporating natural fibre in composite material has seen some potential to be used as a future building construction material due to its recyclability, lightweight and high-reliability feature. However, the issue of implementing natural fibre as building construction material in composites material concerns the structural integrity of the material. As the characteristics of the natural fibre honeycomb composite have been discovered more in terms of properties which ranges from its physical and chemical structural composition to the quasi-static impact collapse of the material, the absorption energy of the material in different cell geometry is unknown. Therefore, the purpose of this study involves the testing of the natural fibre honeycomb (NFH) composite made from cement fibre (face sheet) and corn starch (core) with regards to its crushing behaviour when subjected to flatwise compression load according to ASTM D-3410 standard to analyse the performance of energy absorption of NFH composite with different thicknesses of the hexagonal core and cell wall thickness to determine the Specific Energy Absorption of the material. The result obtained shows that the increasing thicknesses of the core and cell wall improves the ability of the composite to absorb more energy and the specific energy absorption is higher when both factors are increased.
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SULOCHANI, R. M. N., R. A. JAYASINGHE, A. H. L. R. NILMINI e Gayan Priyadarshana. "Recent Developments in Textile Reinforced Polymer Composites". Asian Journal of Chemistry 34, n. 3 (2022): 487–96. http://dx.doi.org/10.14233/ajchem.2022.23504.
Testo completoAbstract (sommario):
This article provides an overview of using textile materials as reinforcement in polymer composites. A considerable amount of research studies on this topic have been conducted to date. The different types of textile materials and polymer matrices used in composite development have been discussed. The fabrication techniques used in the development of composites, the properties, testing methods and the specific standards have been critically reviewed. Furthermore, the suitable applications of textile reinforced polymer composites are reviewed. This review highlights the potential of textile materials in polymer matrices as reinforcement for various applications, including automotive, aeronautical, defence, construction industries, etc.
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Pike, Graham E., Nicola A. Brace, Jim Turner e Annelies Vredeveldt. "The Effect of Facial Composite Construction on Eyewitness Identification Accuracy in an Ecologically Valid Paradigm". Criminal Justice and Behavior 46, n. 2 (8 novembre 2018): 319–36. http://dx.doi.org/10.1177/0093854818811376.
Testo completoAbstract (sommario):
Previous research has produced equivocal results with regard to whether facial composite creation affects subsequent eyewitness identification accuracy, but the most widely publicized view is that creating a composite impairs the ability to later recognize the perpetrator from a line-up. In our first experiment, we examined this effect using several ecologically valid elements including a live staged crime, trained police officers, and a long delay between construction and identification, albeit with only a short delay between crime and composite construction. Composite construction did not significantly affect line-up identification accuracy. Experiment 2 replicated this result using a laboratory-based design and sequential line-up task, eliminating the possibly confounding effect of differential levels of motivation and relative judgments. Taken together, the experiments suggest composite creation may not negatively impact subsequent line-up accuracy, regardless of whether an ecologically valid method or more standard laboratory testing was used.
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Kong, Ing, Kay Min Khoo, Oliver Buddrick, Abdul Aziz Baharuddin e Pooria Khalili. "Synthesis and Characterization of Red Mud and Sawdust Based Geopolymer Composites as Potential Construction Material". Materials Science Forum 923 (maggio 2018): 130–34. http://dx.doi.org/10.4028/www.scientific.net/msf.923.130.
Testo completoAbstract (sommario):
The aim of this study was to synthesize the geopolymer composites formed by two industrial wastes, namely red mud (RM) and saw dust (SD). SD was chemically treated with alkali for the removal of lignin and subsequently bleached, before forming composite with acid-modified RM. The composites were then characterized by using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetic analysis (TGA) and universal testing machine to study the morphology, chemical, thermal and mechanical properties. The FTIR spectrum showed that Si and Al from the raw materials played the major role in forming aluminosilicate geopolymer composites. The SEM images revealed that SD and RM particles aggregated to form fully condensed geopolymer matrices with high compressive strength of 8.3-138 MPa, which were comparable to Portland cement (compressive strength of 9-20.7 MPa).
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Ryu, H. K., C. S. Shim e S. P. Chang. "Testing a composite box-girder bridge with precast decks". Proceedings of the Institution of Civil Engineers - Structures and Buildings 157, n. 4 (agosto 2004): 243–50. http://dx.doi.org/10.1680/stbu.2004.157.4.243.
Testo completo
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Kutz, Philipp Werner, Jan Werner e Frank Otremba. "Testing of Composite Material for Transport Tanks for LNG". Key Engineering Materials 809 (giugno 2019): 625–29. http://dx.doi.org/10.4028/www.scientific.net/kem.809.625.
Testo completoAbstract (sommario):
To reduce the emission of carbondyoxide (CO2) of combustion engines, liquefied naturalgas (LNG) is used as an alternative fuel. LNG is transported via truck, ship or railway for longdistances. Double walled stainless steel tanks are used for transportation, which are heavy and expensive.The vacuum insulation between the two walled structure ensures that the LNG stays liquid overthe transportation time (boiling point of LNG: −162 °C). This causes a high temperature differencebetween the transported good and the ambient air. A simplified tank construction is used to reduce the weight and price of the tank. Instead of stainlesssteel, glass fiber reinforced plastic (GFRP) is used. The designed is changed to a single walledconstruction with a solid insulation material outside on the GFRP structure. Goal of this work is the characterization of a suitable insulation material and configuration as wellas the analysis of the mechanical properties of GFRP under cryogenic conditions. Several experimentsare carried out. Numerical models of these experiments can then be used for parameter studies.
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De Corte, Wouter, e Jordi Uyttersprot. "FRP Bridges in the Flanders Region: Experiences from the C-Bridge Project". Applied Sciences 12, n. 21 (27 ottobre 2022): 10897. http://dx.doi.org/10.3390/app122110897.
Testo completoAbstract (sommario):
At the start of the C-Bridge project in 2018, the number of fibre-reinforced composite bridges in the Flanders region of Belgium was limited to a handful. These limited achievements were largely due to the poor knowledge of clients (public and private), project managers, design engineers, and contractors, which made the option of composites either unknown or still viewed with a certain degree of suspicion. In addition, there were no standards at the Belgian or European level for the design of such constructions. The C-Bridge project (roadmap into design, guidelines, and execution of composite bridges in Flanders) aimed to stimulate the design, the realization and the construction of composite bridges in Flanders by providing the necessary knowledge to the construction sector in the most suitable form. This knowledge consists of the current state of the art of composites in bridge construction, selection criteria for composite bridges, recommendations for specification texts, and in situ testing of composite bridges and structural and vibration analysis. This C-Bridge project should allow the awarding authorities and contractors to be able to make informed choices regarding fibre-reinforced polymer (fibre composite) bridges but also offer the possibility of making the necessary transformation to this new and promising material to various Flemish companies. The results of the project enable Flemish clients to draw up specifications for FRP bridges in the correct manner. Moreover, they can correctly interpret the calculation notes made available and make a correct assessment. The Flemish engineering firms, on the other hand, will be able to make their own designs of FRP bridges and bridge components. They can also build up a value chain within Flanders with Flemish contractors and producers. From the producers and suppliers’ point of view, the results of the project will lead to a clearer profile of their products on the public and private market. Finally, the general contractors and constructors will be armed to withstand the challenges that FRP bridges entail to subcontractors in terms of execution, follow-up, delivery, and maintenance. The findings are helpful for the acceptance of fibre-reinforced composite bridges as an alternative to timber, steel, or concrete bridges and should generate a market expansion for FRP in the traditionally conservative bridge-building sector first in Flanders and later internationally.
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Ayyasamy, Leema Rose, Anbarasu Mohan, Dhanasingh Sivalinga Vijayan, Agoramoorthy Sattainathan Sharma, Parthiban Devarajan e Aravindan Sivasuriyan. "Finite element analysis of behavior and ultimate strength of composite column". Science and Engineering of Composite Materials 29, n. 1 (1 gennaio 2022): 176–82. http://dx.doi.org/10.1515/secm-2022-0017.
Testo completoAbstract (sommario):
Abstract Composite sections are found to be a novel technique in modern day scenario of construction. This stands tall than the ordinary and conventional type of constructions. Columns as a structural element play a vital role in structural frame. This research comments on the behavior of composite columns. The main objective of this study is to analyze the behavior of steel-encased concrete composite columns as experimentally under axial compression and the mode of failure under ultimate failure and yield point. The steel-concrete composite system combines the formability and rigidity of reinforced concrete with the ductility and strength of structural steel to meet the demand for earthquake-resistant constructions. Three specimens were chosen for this study: one was a composite column, the other two were ordinary RC columns and structural steel columns. The raw materials' natural properties are assessed. As a result, material testing for cement, fine aggregate, and coarse aggregate was completed, as well as a concrete mix design. A comparative analysis of the local and post-local buckling behavior of different composite sections has been studied and the column sections have been designed according to Eurocode 4 (ENV 1994) to determine the plastic resistance of the section. These three specimens underwent compression test and the results are tabulated and compared. The corrosion resistance and fireproof nature (resistance to fire at higher temperatures) that are transmitted into the member are related to the steel being encased within the concrete. These are the two major drawbacks of any steel construction combined with an earthquake-resistant structure. Rather than a traditional steel construction, earthquake structures benefit from this type of load handling capabilities. The portion can be used before it completely collapses if proper design factors are taken into account.
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Breen, John E., Michael E. Kreger, Christopher D. White e Gordon C. Clark. "Field evaluation and model test of a composite wing-girder bridge". Canadian Journal of Civil Engineering 14, n. 6 (1 dicembre 1987): 753–62. http://dx.doi.org/10.1139/l87-113.
Testo completoAbstract (sommario):
This paper presents the key observations and conclusions from the evaluation of an innovative "loose-fit" composite, post-tensioned concrete wing-girder bridge proposed for an elevated interstate highway expansion in an urban environment. The evaluation program included both testing to destruction of a 1/2-scale model of a partial span as well as construction monitoring and field testing at service load levels of a full-scale prototype two-span bridge. Results of both construction measurements and loading tests were compared with analytical predictions. Laboratory tests showed the composite behavior of the wing-girder joint to be fully effective and a high level of load transfer between wings to be present. Recommendations for modification of the prototype design are made to improve constructibility, durability, structural performance, and economy. Key words: box girder, bridge, post-tensioned, prestressed concrete, reinforcement, stresses, temperature, tendons.
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Dickson, Barry, Hota GangaRao e Vijith Vijayachandran. "Laboratory Testing of Stress-Laminated Wood Decks on Steel Beams". Transportation Research Record: Journal of the Transportation Research Board 1575, n. 1 (gennaio 1997): 47–52. http://dx.doi.org/10.3141/1575-07.
Testo completoAbstract (sommario):
Four different stress-laminated wood decks were laboratory-tested to measure composite action between deck and steel beams, transverse load distribution, performance of connectors, and deck construction cost. The models were subjected to cyclic loading varying from 9 to 89 kN. Static load tests were conducted after every 100,000 cycles. During static testing, strains and deflections in the beams were measured at 22, 44, 67, and 89 kN. The loss of tension in the connectors was also monitored after every 100,000 cycles. The readings were used to compare the composite action, load distribution, and tension loss in connectors. Load distribution values were verified with theoretical calculations.
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Xiang, Xian Chao, Guo Sheng Jiang e Chang Qi Zhu. "Testing Study on DJM Pile Composite Foundation under Flexible Load". Advanced Materials Research 168-170 (dicembre 2010): 2513–17. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.2513.
Testo completoAbstract (sommario):
Dry jet mixing (DJM) piles are widely used in silt foundation treatment to improve foundation stability and control post-construction deformation. As the work mechanism of DJM composite foundation is very complex, though many useful calculation theories have achieved, the theoretical study of DJM pile composite foundation is still far behind engineering practice, the settlement and stress calculation precision is unsatisfied. Then it is still necessary to reveal the work mechanism of DJM pile comprehensively. A field test of DJM pile composite road foundation is carried out and many measurement methods are adopt to collect the test information, such as soil pressure sensors, pore pressure sensors, settlement plates, inclinometer tubes, stratified settlement pipes, multi-point displacement meters in piles and so on. Then the surface settlement, internal deformation and stress developing of soils and piles are monitored Real-time. Through in-site test, the settlement and internal deformation of piles and soils, the stress ratio between pile and soil, and the negative friction around pile are studied.
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Latroch, N., A. S. Benosman, N. Bouhamou, B. Belbachir, Y. Senhadji, H. Taïbi e M. Mouli. "Testing of Composite Mortars Based on Supplementary Cementitious Materials: Estimating Durability and Thermal Properties". International Journal of Engineering Research in Africa 27 (dicembre 2016): 27–35. http://dx.doi.org/10.4028/www.scientific.net/jera.27.27.
Testo completoAbstract (sommario):
The growing need for building material resources, and the requirements to preserve the environment, in a vision of sustainable development, has become necessary to study reinforcement techniques, using composite materials. Using local organic or inorganic materials in construction fields and public works is particularly important. Polymer mortar composites (PMC) are usually employed in the building industry as finishing materials, tile adhesive (mortar-adhesive) or façade coating. In repair applications, the addition of soluble polymer (latex) allows improving the adhesion properties of the materials used as coating. The use of mineral additives as partial substitutes for cement, in construction sites as well as in ready-to-use mortars, is an unknown practice in our country. For this reason, we thought it is crucial to study and assess the influence of these additions on the properties of cured composite. Supplementary cementitious materials (SCM) used in this study are silica fume and natural pozzolan, which necessarily need to be valorized.The present research work aims to use a specific experimental methodology that is able to identify the relationship between the degree of substitution by the mineral additives, the polymer and the modifications to the properties of fresh and hardened cement mixtures. Therefore, five PMC combinations were formulated from different percentages of additions, i.e. natural pozzolan (NP: 25%w), silica fume (Sf: 5%w) and polymer latex (P: 0, 5, 7.5, 10, 12.5 and 15%w). Their durability factors, such as the porosity accessible to water and capillary absorption rate (sorptivity), were characterized, at different maturities. An attempt was also made to determine the thermal coefficients. The results obtained were compared with those of the reference mortars, made with Portland cement (CEMI). They showed that the decrease in porosity, sorptivity and thermal conductivity depends on the pair “SCMs/polymer”. But overall, the addition of polymer latex and pozzolanic additions have a beneficial effect on the durability and thermal properties of the composite materials.
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Luo, Ting, e Qiang Wang. "Effects of Graphite on Electrically Conductive Cementitious Composite Properties: A Review". Materials 14, n. 17 (24 agosto 2021): 4798. http://dx.doi.org/10.3390/ma14174798.
Testo completoAbstract (sommario):
Electrically conductive cementitious composites (ECCCs) have been widely used to complete functional and smart construction projects. Graphite, due to its low cost and wide availability, is a promising electrically conductive filler to generate electrically conductive networks in cement matrixes. Cement-based materials provide an ideal balance of safety, environmental protection, strength, durability, and economy. Today, graphite is commonly applied in traditional cementitious materials. This paper reviews previous studies regarding the effects and correlations of the use of graphite-based materials as conductive fillers on the properties of traditional cementitious materials. The dispersion, workability, cement hydration, mechanical strength, durability, and electrically conductive mechanisms of cementitious composites modified with graphite are summarized. Graphite composite modification methods and testing methods for the electrical conductivity of ECCCs are also summarized.
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Oravec, Pavel, e Michal Hamala. "Acoustic Qualities of a Ceiling From Prefabricated Timber – Concrete Composite Panels / Akustické Vlastnosti Stropu Z Prefabrikovaných Dřevo – Betonových Spřažených Panelů". Transactions of the VŠB – Technical University of Ostrava, Civil Engineering Series 12, n. 2 (1 dicembre 2012): 117–22. http://dx.doi.org/10.2478/v10160-012-0025-3.
Testo completoAbstract (sommario):
Abstract This article describes the acoustic qualities (sound insulation and a level of acoustic pressure of impact sound) composite construction, composite timber - concrete ceiling. The qualities of the ceiling construction were discovered in the experimental measurements in the acoustic testing laboratory certified by CSI Zlin on a sample of a 3 x 3,6 m size. One type of a floor composition was created. Three phases of measurement have been performed on the tested floor. The aim of the experiment was to determine whether the devised ceiling can be used as a separating element between apartments.
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Joustra, Jelle, Conny Bakker, Riel Bessai e Ruud Balkenende. "Circular Composites by Design: Testing a Design Method in Industry". Sustainability 14, n. 13 (30 giugno 2022): 7993. http://dx.doi.org/10.3390/su14137993.
Testo completoAbstract (sommario):
The design of composite products for a circular economy is challenging. Materials such as glass-fibre-reinforced plastics have long product lifetimes but are hard to recycle. For the effective reuse and recycling of products, parts, and materials, recovery strategies must be selected and implemented in the product design stage. This extends the scope and complexity of the design process and requires additional skills from the designers. We developed a novel circular composites design method for products containing composite materials to support designers and improve product circularity. This method, which is the first of its kind to address the circular design of composite products, helps designers explore recovery pathways and generate design solutions. In this study, we evaluated the method’s effectiveness, accessibility, and usability in design practice. We tested the method with five design case studies in the construction, furniture, and automotive industries. The method was used to generate, evaluate, communicate, and detail product designs. We found that two of the five cases used the method to develop circular product concepts. In the other three cases, recycling rather than product-level recovery strategies was the result, with a focus on improving the material formulations instead of the overall product design. Although the designers considered the method accessible and usable, its effectiveness was restricted by the existing business, logistics, reprocessing technology, and policy contexts. These factors are intertwined and partly dictate the boundary conditions of the design, which means that to successfully implement the proposed method, the transition to a circular economy requires a holistic approach to adjust the design process, organisations, and value chains.
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Zhang, Dongfang, Junhai Zhao e Shuanhai He. "Cyclic Testing of Concrete-Filled Double-Skin Steel Tubular Column to Steel Beam Joint with RC Slab". Advances in Civil Engineering 2018 (26 luglio 2018): 1–15. http://dx.doi.org/10.1155/2018/7126393.
Testo completoAbstract (sommario):
The design of composite joints for connecting concrete-filled double-skin tubular (CFDST) columns to steel beams supporting reinforced concrete (RC) slabs is presented in this paper. Five half-scale specimens were designed, including four composite joints with RC slab and one bare steel beam joint, and were tested under a constant axially compressive force and lateral cyclic loading at the top end of the column to evaluate their seismic behavior. The main experimental parameters were the construction of the joint and the type of the column. The seismic behaviors, including the failure modes, hysteresis curves, ductility, strength and stiffness degradation, and energy dissipation, were investigated. The failure modes of the composite joints depended on the joint construction and on the stiffness ratio of beams to columns. Joints of stiffening type had significantly higher load-bearing and deformation capacities than joints of nonstiffening type. Compared with the bare steel beam joint, the bearing capacities of the composite joints with RC slabs were markedly increased. The composite action was remarkable under sagging moments, resulting in larger deformation on the bottom flanges of the beams. Overall, most specimens exhibited full hysteresis loops, and the equivalent viscous damping coefficients were 0.282∼0.311. The interstory drift ratios satisfied the requirements specified by technical regulations. Composite connections of this type exhibit excellent ductility and favorable energy dissipation and can be effectively utilized in superhigh-rise buildings erected in earthquake zones.
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Topič, Jaroslav, Zdeněk Prošek, Josef Fládr, Václav Nežerka e Pavel Tesárek. "Replacement of Cement with Finely Ground Recycled Concrete: Influence on Mechanical Properties". Applied Mechanics and Materials 825 (febbraio 2016): 69–72. http://dx.doi.org/10.4028/www.scientific.net/amm.825.69.
Testo completoAbstract (sommario):
The waste production from construction sites become very serious problem. Recycling is the best option for disposal of such waste, and the proper sorting and knowledge of the recycled concrete history allows its further use in the construction. The current studies are mostly focused on utilization of recycled concrete in the form of aggregate. The presented work is focused on the utilization of Finely Ground Recycled Concrete (FGRC) used as a filler and partial substitution for binder. Recycled concrete was ground from concrete railway sleepers in the Lavaris Company (Czech Republic). Through the testing of mechanical properties, we demonstrate the influence of FGRC’s amount in cement paste on mechanical properties of the composite. To clearly show the relationship between the amount of FGRC and the composite properties, samples with 33, 67 and 100 wt. % of cement replaced by FGRC were tested. The composite with 33 wt. % of FGRC attained the compressive and flexural strength comparable with reference cement paste without any FGRC additions. The results indicate that the partial substitution of cement by FGRC could lead to a cost reduction of cement composites with minimal impact on their mechanical properties.