Journal articles on the topic 'Beams'
To see the other types of publications on this topic, follow the link: Beams.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Beams.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Lv, Yu, Hong Juan Cui, Pei Tao Dong, Zhi Hua Chen, and Xue Zhong Wu. "A Silicon Micro-Accelerometer with Triangle Cross-Section Beam by Anisotropic Wet Etching in TMAH Solution." Key Engineering Materials 503 (February 2012): 151–55. http://dx.doi.org/10.4028/www.scientific.net/kem.503.151.
Full textAbstract:
A capacitive accelerometer with triangle cross-section beam fabricated by anisotropic wet etching of (100) silicon is presented in this paper. The feature of this accelerometer is that eight suspension beams with triangle cross-section are formed by anisotropic wet etching of (100) silicon in TMAH solution, without heavy boron doping or Si-Si bonding. When the width of beam is decided, the beam’s geometry is determinate. The formation procedure of the triangle cross-section beam is analyzed in detail. Through this beam-fabrication approach, the beam’s thickness can be well controlled by beam’s width and intrinsic stress in the beams is minimized. Accelerometers with different sensitivities can be easily fabricated by varying the width of the beams. For a device with 23 μm width beams, the resonance frequency and the quality factor are 644 Hz and 32, respectively. The sensitivity of accelerometer is measured as 2 V•g-1.
2
Elkafrawy, Mohamed, Ahmed Khalil, Mohammad AlHamaydeh, Rami Hawileh, and Wael Abuzaid. "Enhancing the Shear Capacity of RC Beams with Web Openings in Shear Zones Using Pre-Stressed Fe-SMA Bars: Numerical Study." Buildings 13, no. 6 (June 11, 2023): 1505. http://dx.doi.org/10.3390/buildings13061505.
Full textAbstract:
Openings in the shear span can significantly affect the structural behavior of reinforced concrete (RC) beams, particularly in terms of shear capacity and crack propagation. This paper aims to investigate the feasibility of strengthening the web opening in the shear zone of RC beams by using iron-based shape memory alloy (Fe-SMA) bars, providing valuable insights for structural engineers and researchers. Numerical analysis with ABAQUS/CAE 2020 software was employed in the current study. The research was divided into six groups of beams with web openings of different lengths (150, 300, and 450 mm), prestressing levels (0%, 30%, and 60%), and reinforcement diameters (14, 18, and 22 mm) of Fe-SMA bars. The results show that the presence of web openings can cause a significant reduction in the cracking and ultimate loads of the beams, with reductions ranging from 11% to 50% and 36% to 48%, respectively. However, by adding pre-stressed Fe-SMA bars around small web openings (100 × 150 mm), the shear capacity of the beam is restored, and the beam exhibits behavior similar to solid beams. Additionally, activating the Fe-SMA bars by 30% and 60% resulted in almost similar cracking loads but improved load-carrying capacity of the beam with small openings by 12% and 9%, respectively, compared to the solid beam. The technique proposed for enhancing shear strength is most effective for beams with small (100 × 150 mm) and medium (100 × 300 mm) web openings as it can restore both the beam’s shear strength and stiffness. However, for beams with larger web openings (100 × 450 mm), the use of activated Fe-SMA beams can recover almost 90% of the solid beam’s shear capacity. Furthermore, reinforcing small openings with Fe-SMA bars of different diameters enhances beam shear capacity and stiffness, while for larger openings, higher Fe-SMA reinforcement ratios could potentially restore the beam’s full strength and stiffness. This study emphasizes the importance of strengthening web openings in RC beams, particularly in shear zones, and provides significant insights into how to strengthen beams with web openings, thereby contributing to developing safer structures. However, further laboratory experiments are recommended to validate, complement and extend the findings of this numerical study.
3
Salem, Osama (Sam). "Parametric study on load ratio effect on the flexural bending behaviour of axially-restrained HSS steel beams subjected to fire." Journal of Structural Fire Engineering 9, no. 4 (December 10, 2018): 342–60. http://dx.doi.org/10.1108/jsfe-10-2017-0042.
Full textAbstract:
Purpose In fire condition, the limiting temperature of a restrained steel beam depends on a few parameters, e.g. temperature distributions along and across the beam, beam’s load ratio and span length. The purpose of this study is to investigate the structural fire behaviour of axially restrained steel beams under different beam’s load ratios, taking into consideration the effect of the beam’s end connections configuration. Design/methodology/approach A three-dimensional finite element (FE) computer model has been developed to simulate the structural fire behaviour of axially restrained steel beams and their end connections. After successfully validating the developed model against the outcomes of the available large-size fire resistance experiments, the FE model has been used in a parametric study to investigate the beam’s load ratio effect on the behaviour of the axially restrained steel beams and their end connections. Findings The parametric study showed that increasing the beam loading level significantly increased the beam deflections at elevated temperatures; where, increasing the beam’s load ratio from 0.5 to 0.9 reduced the beam fire resistance by about 100 s. In contrast, decreasing the beam’s load ratio from 0.5 to 0.3 allowed the beam to easily achieve a 30-min fire resistance rating with no fire protection applied. Originality/value Experimental parametric studies are difficult to control in a laboratory setting and are also expensive and time consuming. Therefore, the reasonable accuracy of the validated FE model in reproducing the experimental fire behaviour of steel beams and their end connections makes it a very useful tool for both numerical and analytical studies.
4
Siew, Jia Ning, Qi Yan Tan, Kar Sing Lim, Jolius Gimbun, Kong Fah Tee, and Siew Choo Chin. "Effective Strengthening of RC Beams Using Bamboo-Fibre-Reinforced Polymer: A Finite-Element Analysis." Fibers 11, no. 5 (April 22, 2023): 36. http://dx.doi.org/10.3390/fib11050036.
Full textAbstract:
This paper presents a finite-element model of the structural behaviour of reinforced concrete (RC) beams with and without openings externally strengthened with bamboo-fibre-reinforced composite (BFRC) plates. The simulation was performed using ABAQUS Unified FEA 2021HF8 software. The stress–strain relationship of the RC was modelled using a model code for concrete structures, whereas the concrete-damaged plasticity model was used to simulate concrete damage. The predicted crack pattern of the beams was comparable to that from experimental observations. The ultimate load-bearing capacity of RC beams in flexure was predicted with an error of up to 1.50%, while the ultimate load-bearing capacity of RC beams with openings in shear was predicted with an error ranging from 1.89 to 13.43%. The most successful arrangement for strengthening a beam with openings in the shear zone was to place BFRC plates perpendicular to the crack on both sides of the beam’s surface, which increased the beam’s original load-bearing capacity by 110.06% compared to that of the control beam (CB). The most effective method for strengthening RC beams in flexure is to attach a BFRC plate to the entire bottom soffit of the RC beam. This maximises the ultimate load-bearing capacity at the expense of the beam’s ductility.
5
Awaludin, Ali, and Urwatul Wusqo. "Flexural Resistance of LVL Sengon Beams with Lateral Stiffener at Both Ends." MEDIA KOMUNIKASI TEKNIK SIPIL 27, no. 2 (December 30, 2021): 170–78. http://dx.doi.org/10.14710/mkts.v27i2.35911.
Full textAbstract:
Slender beams (beams having a large section height to width ratio ( )) are commonly used in a structure that needs a large bending moment capacity. However, the use of slender beams in a structure is susceptible to overturning and torsion occurrence. Therefore, lateral bracing is usually placed in several points of the beam to prevent lateral-torsional buckling. In this study, a three-point bending test was conducted to evaluate the capacity of 250 mm x 50 mm x 2500 mm Laminated Veneer Lumber (LVL) beams made from Sengon. Two lateral supports were placed at both ends to prevent the beam's lateral displacement. The bending test result shows that the ultimate load of the LVL beam reach 27.88 kN before failure. Furthermore, the LVL beams' bending capacity was calculated using the mechanical properties provided by several previous studies. The LVL beam's capacity was predicted using manual calculation (based on SNI 7973: 2013) and numerical analysis. Numerical analysis was performed using ABAQUS software, and the results were evaluated using the Tsai-Hill and maximum strain failure criterion. The results showed that the maximum strain criterion provides a better prediction of the LVL beam's capacity than Tsai-Hill failure criterion.
6
Thang, Nguyen Truong, and Nguyen Hai Viet. "Simplified calculation of flexural strength deterioration of reinforced concrete T-beams exposed to ISO 834 standard fire." Journal of Science and Technology in Civil Engineering (STCE) - HUCE 15, no. 4 (October 31, 2021): 123–35. http://dx.doi.org/10.31814/stce.huce(nuce)2021-15(4)-11.
Full textAbstract:
Reinforced concrete (RC) T-shaped cross-section beam (so-called T-beam) is a common structural member in buildings where beams and slabs are monolithically cast together. In this paper, a simplified calculation method based on Russian design standard SP 468.1325800.2019 is introduced to determine the flexural strength of RC T-beams when exposed to ISO 834 standard fire. The idea of 500oC isotherm method, which is stipulated in both Eurocodes (EC2-1.2) and SP 468, is applied associated with specifications of temperature distribution on T-beams’ cross sections and the temperature-dependent mechanical properties of concrete and reinforcing steel. A case study is conducted to explicitly calculate the flexural strength deterioration (FSD) of T-beams compared to that at ambient temperature. A calculation sheet is established for parametric studies, from which the results show that the FSD factor of RC T-beams is adversely proportional to the dimensions of the beam’s web and flange. However, the effect of these components of T-beams is not significant.
7
Hildén, P., E. Ilina, M. Kaivola, and A. Shevchenko. "Multifrequency Bessel beams with adjustable group velocity and longitudinal acceleration in free space." New Journal of Physics 24, no. 3 (March 1, 2022): 033042. http://dx.doi.org/10.1088/1367-2630/ac5aef.
Full textAbstract:
Abstract The group velocity of an optical beam in free space is usually considered to be equal to the speed of light in vacuum. However, it has been recently realized that, by structuring the beam’s angular and temporal spectra, one can achieve well pronounced and controlled subluminal and superluminal propagation. In this work, we consider multifrequency Bessel beams that are known to propagate without divergence and show a variety of possibilities to adjust the group velocity of the beam by means of designed angular dispersion. We present several examples of multifrequency Bessel beams with negative and arbitrary positive group velocities, as well as longitudinally accelerating beams and beams with periodically oscillating local group velocities. The results of these studies can be of interest to scientists working in the fields of optical beam engineering, light amplitude and intensity interferometry, ultrafast optics, and optical tweezers.
8
Sheng, Jie, Zongjian Yu, Guotao Dou, and Hao Liu. "Fatigue Damage Behaviors of TRC-Strengthened RC Beams." Materials 15, no. 15 (July 22, 2022): 5113. http://dx.doi.org/10.3390/ma15155113.
Full textAbstract:
For the investigation of fatigue damage behavior of textile reinforced concrete (TRC)-strengthened RC beams, in this study, eight RC beams were fabricated, and five of them were strengthened with TRC and tested under fatigue loading until failure, using a four-point bending setup. Research parameters included reinforcement ratio, textile ratio, and strengthening methods (single-side and U-wrapped). The failure mode, fatigue life, fatigue deformation, and other properties of TRC-strengthened beams were analyzed. Experimental results revealed that there were two fatigue failure modes for TRC-strengthened RC beams. In the first mode, the textile was snapped, but the steel bars did not rupture. In the second mode, both the textile and steel bars broke. Fatigue failure modes depended on the textile ratio. The TRC-strengthened beam’s fatigue life was significantly higher than the non-strengthened RC beam. At the same textile ratio, the TRC-strengthened beam’s fatigue life using the single-side method was longer than that using the U-wrapped method. With the increase in fatigue loading time, the midspan deflection of the TRC-strengthened beam was developed in three stages, namely rapid development stage, stable development stage, and destabilized development stage. The residual deflection and strain damage accumulation of tensile steel bars of TRC-strengthened beams were significantly reduced with the increase in textile or reinforcement ratios; thus, the beam’s fatigue life was prolonged.
9
Słowik, Marta. "Analysis of fracture processes in reinforced concrete beams without stirrups." Frattura ed Integrità Strutturale 15, no. 57 (June 22, 2021): 321–30. http://dx.doi.org/10.3221/igf-esis.57.23.
Full textAbstract:
The analysis of fracture processes which led to shear failure in reinforced concrete beams without transverse reinforcement was performed on the basis of test results from the author’s own experimental investigation and numerical simulations. The variable parameters during the experiment were a beam’s length and a shear span. It was observed that the character of failure in the beams depended on the beam’s length and the span-to-depth ratio. In slender beams characterized by the shear span-to-depth ratio 3.4 and 4.1, the formation of the critical diagonal crack caused a brittle, sudden failure and the shear capacity was low. In short beams, when the shear span-to-depth ratio was 1.8 and 2.3, the failure process had a more stable character with a slow developing of inclined cracks and the significantly higher load capacity was reached. The activation of various shear transfer mechanisms was examined with regard to the slenderness of the member and the transition between a beam action which took place in slender beams to an arch action which predominated in short beams was described.
10
Muhtar, Amri Gunasti, Suhardi, Nursaid, Irawati, Ilanka Cahya Dewi, Moh Dasuki, et al. "The Prediction of Stiffness of Bamboo-Reinforced Concrete Beams Using Experiment Data and Artificial Neural Networks (ANNs)." Crystals 10, no. 9 (August 27, 2020): 757. http://dx.doi.org/10.3390/cryst10090757.
Full textAbstract:
Stiffness is the main parameter of the beam’s resistance to deformation. Based on advanced research, the stiffness of bamboo-reinforced concrete beams (BRC) tends to be lower than the stiffness of steel-reinforced concrete beams (SRC). However, the advantage of bamboo-reinforced concrete beams has enough good ductility according to the fundamental properties of bamboo, which have high tensile strength and high elastic properties. This study aims to predict and validate the stiffness of bamboo-reinforced concrete beams from the experimental results data using artificial neural networks (ANNs). The number of beam test specimens were 25 pieces with a size of 75 mm × 150 mm × 1100 mm. The testing method uses the four-point method with simple support. The results of the analysis showed the similarity between the stiffness of the beam’s experimental results with the artificial neural network (ANN) analysis results. The similarity rate of the two analyses is around 99% and the percentage of errors is not more than 1%, both for bamboo-reinforced concrete beams (BRC) and steel-reinforced concrete beams (SRC).
11
Kovacikova, Janka, Olga Ivankova, and Dusan Drobny. "An Influence of a Shape of a Flaw on a Value of Stress on Beams." Applied Mechanics and Materials 837 (June 2016): 230–33. http://dx.doi.org/10.4028/www.scientific.net/amm.837.230.
Full textAbstract:
The main topic of this paper is finite element analysis of 4-point loaded glulam beams which contain different types of flaws. There were modeled four types of beams. First type was the beam without a flaw, second was the beam with a central crack in the middle of span located at the bottom edge of the beam, third model of beams contained also the central crack but this crack was located 20 mm above the edge and the last model contained a hole in the middle of the span as simulation of a knot. These models were performed and analyzed in ANSYS. Task was considered as two dimensional. There were compared values of stress in different types of beam's models.
12
Shulemovich, Alexander. "Advanced theory of vibration of uniform beams." International Journal of Engineering & Technology 7, no. 1 (January 19, 2018): 70. http://dx.doi.org/10.14419/ijet.v7i1.8748.
Full textAbstract:
In classical theory the equation of a dynamic Euler – Lagrange beam is solved by using the composition of the displacements into the sum of harmonic vibrations to obtain the ordinary differential equation. The solution of this equation with prescribed set of boundary conditions is a typical Sturm – Liouville problem with the infinite, discrete eigenvalues and modes of vibration. The purpose of this paper is to reveal that an elastic beam is a limited continuum with limited domain of physically existing, continuous eigenvalues and modes of vibration. In contrast to the classical theory, the advanced theory of free vibration of beams without damping in present investigation is based on the analysis with transversal and angular stiffness, initiated by external transient excitations and inherited by beams in compliance with energy conservation law. The output of this investigation demonstrates the fundamental distinction between the dynamic characteristics of uniformed beams established by classical theory with infinite, discrete eigenvalues and derived characteristics of beams with continuous eigenvalues and modes of vibration in limited domains. The theoretical investigation shows that only few, natural, discrete eigenvalues and normal modes of vibration physically exist in limited domains.Nomenclature: k4 = ω2a−2, a2 = E I g (A γ) −1, E − modulus of elasticity, g − gravitational acceleration, A − area of the beam’s cross - section, γ − specific gravity of the beam’s material, ω = 2πf, f − frequency of vibration per second, angular frequency p = a (kl)2/l2, I – length of beam. I − moment of inertia of area.
13
Zhang, Yuwei, Yongchun Cheng, Guojin Tan, Xiang Lyu, Xun Sun, Yunshuo Bai, and Shuting Yang. "Natural Frequency Response Evaluation for RC Beams Affected by Steel Corrosion Using Acceleration Sensors." Sensors 20, no. 18 (September 17, 2020): 5335. http://dx.doi.org/10.3390/s20185335.
Full textAbstract:
This paper presented a laboratory investigation for analyzing the natural frequency response of reinforced concrete (RC) beams affected by steel corrosion. The electrochemical acceleration technique induced the corroded RC beams until the predetermined value of the steel corrosion ratio was achieved. Then, the natural frequency responses of the corroded beams were tested utilizing piezoelectric acceleration sensors. The damage states of the corroded beams were assessed through the measurement of crack parameters and the equivalent elastic modulus of the beams, which aims to clarify the fundamental characteristics of the dynamic response for the corroded RC beam with the increased steel corrosion ratio. The results revealed that steel corrosion reduces the bending stiffness of the RC beams and, thus, reduces the modal frequency. The variation of natural frequency can identify the corrosion damage even if no surface cracking of the RC beam, and the second-order frequency should be more indicative of the damage scenario. The degradations of stiffness and the natural frequency were estimated in this study by the free vibration equation of a simply supported beam, and a prediction method for the RC beam’s residual service life was established. This study supports the use of variations in natural frequency as one diagnostic indicator to evaluate the health of RC bridge structures.
14
Yang, Yuanjie, Xinlei Zhu, Jun Zeng, Xingyuan Lu, Chengliang Zhao, and Yangjian Cai. "Anomalous Bessel vortex beam: modulating orbital angular momentum with propagation." Nanophotonics 7, no. 3 (February 23, 2018): 677–82. http://dx.doi.org/10.1515/nanoph-2017-0078.
Full textAbstract:
AbstractZero-order and higher-order Bessel beams are well-known nondiffracting beams. Namely, they propagate with invariant profile (intensity) and carry a fixed orbital angular momentum. Here, we propose and experimentally study an anomalous Bessel vortex beam. Unlike the traditional Bessel beams, the anomalous Bessel vortex beam carries decreasing orbital angular momentum along the propagation axis in free space. In other words, the local topological charge is inversely proportional to the propagation distance. Both the intensity and phase patterns of the generated beams are measured experimentally, and the experimental results agree well with the simulations. We demonstrate an easy way to modulate the beam’s topological charge to be an arbitrary value, both integer and fractional, within a continuous range. The simplicity of this geometry encourages its applications in optical trapping and quantum information, and the like.
15
Pawar, V. S., S. R. Kokare, S. D. Patil, and M. V. Takale. "Domains of modulation parameter in the interaction of finite Airy–Gaussian laser beams with plasma." Laser and Particle Beams 38, no. 3 (September 2020): 204–10. http://dx.doi.org/10.1017/s0263034620000270.
Full textAbstract:
AbstractIn this paper, self-focusing of finite Airy–Gaussian (AiG) laser beams in collisionless plasma has been investigated. The source of nonlinearity considered herein is relativistic. Based on the Wentzel–Kramers–Brillouin (WKB) and paraxial-ray approximations, the nonlinear coupled differential equations for beam-width parameters in transverse dimensions of AiG beams have been established. The effect of beam's modulation parameter and linear absorption coefficient on the self-focusing/defocusing of the beams is specifically considered. It is found that self-focusing/defocusing of finite AiG beams depends on the range of modulation parameter. The extent of self-focusing is found to decrease with increase in absorption.
16
Hawileh, R., J. A. Abdalla, and Adil K. Al-Tamimi. "Flexural Performance of Strengthened RC Beams with CFRP Laminates Subjected to Cyclic Loading." Key Engineering Materials 471-472 (February 2011): 697–702. http://dx.doi.org/10.4028/www.scientific.net/kem.471-472.697.
Full textAbstract:
Seismic retrofitting of reinforced concrete (RC) beams by means of carbon fiber reinforced polymer (CFRP) composites is one of the state-of-the-art techniques that have been widely practiced lately. Such external strengthening schemes seem to enhance both stiffness and strength of RC beams when subjected to static and cyclic loading. Extensive research investigation has been carried out for beams subjected to monotonic static loading while limited research data is available for beams subjected to cyclic loadings. Therefore, this study is initiated and its aim is to present the results of full scale experimental testing of RC beams under four-point-bending loading and subjected to monotonic and cyclic loading histories up to failure of the specimens. An unstrengthened RC beam was tested monotonically to serve as a bench-mark. The remaining two externally strengthened RC beams with different anchorage schemes were tested under cyclic loading. The strengthening test matrix included beams bonded with a unidirectional CFRP plate that covers 90% of the beam's soffit length, with one or two unidirectional layers of CFRP wraps at anchorage locations along the beam's length. The anchorage locations were at the edges of the CFRP plate and at the middle of the beam's span. The results presented herein show an increase in the overall strength for the strengthened beams over the unstrengthened ones. The different failure modes and the resulting ductility of the tested specimens are also discussed. This study is considered to be the first part of an extensive program that aims to investigate the different parameters that govern the external strengthening techniques of RC beams when subjected to cyclic loading.
17
Liu, Ming, Hua Huang, Jian Ling Hou, and Bo Quan Liu. "Experimental Study on Shear Behavior of RC Beams Strengthened with Stainless Steel Wire Mesh." Advanced Materials Research 243-249 (May 2011): 5582–88. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.5582.
Full textAbstract:
Rehabilitation of RC members with stainless steel wire mesh and permeability polymer mortar is a new method of structural strengthening with the advantages of resistance to fire, corrosion and ageing. Experiments were conducted to investigate the shear behavior of eight strengthened RC rectangular beams and one comparative RC beam. The shear mechanism of strengthened beams was analyzed, and the influences of the strengthening manners, bolts’ amount, bolts’ distance on the shear behavior of strengthened beams were discussed. The test results show that the rehabilitation greatly increase the beam’s shear load-carrying capacity, shear stiffness, and its ductility. But the range of load capacity improvement is greatly influenced by the bolts’ amount and distance, too much and dense bolts badly weaken the shear behavior of beam itself. The influences of the strengthening manners on the load capacity are puny, but the beams’ failure modes are different.
18
Sharaky, Ibrahim A., Ahmed S. Elamary, and Yasir M. Alharthi. "Flexural Response and Failure Analysis of Solid and Hollow Core Concrete Beams with Additional Opening at Different Locations." Materials 14, no. 23 (November 25, 2021): 7203. http://dx.doi.org/10.3390/ma14237203.
Full textAbstract:
It is essential to make openings in structural concrete elements to accommodate mechanical and electrical needs. To study the effect of these openings on the performance of reinforced concrete (RC) elements, a numerical investigation was performed and validated using previous experimental work. The effect of the position and dimension of the opening and the beam length on the response of the beams, loads capacities, and failure modes was studied. The simulated RC beams showed different responses, loads capacities, and failure modes depending on the position and dimension of the opening. The transversal near support opening (TNSH) and longitudinal holes (LH) showed lower effects on the load capacities of the beams than the transversal near center opening (TNCH). The supreme reduction percentages of the load capacity (µu%) for beams with TNCH and TNSH were 37.21% and 30.34%, respectively (opening size = 150 × 150 mm2). In addition, the maximum µu% for beam with LH was 17.82% (opening size = 25% of the beam size). The TNSH with a width of less than 18.18% of the beam shear span (550 mm) had trivial effects on the beam’s load capacities (the maximum µu% = 1.26%). Although the beams with combined LH and TNCH or LH and TNSH showed different failure modes, they experienced nearly the same load reductions. Moreover, the length of the beam (solid or hollow) had a great effect on its failure mode and load capacity. Finally, equations were proposed and validated to calculate the yield load and post-cracking deflection for the concrete beams with a longitudinal opening.
19
Salem, Ghada G., Vera V. Galishnikova, S. M. Elroba, Nikolai I. Vatin, and Makhmud Kharun. "Finite Element Analysis of Self-Healing Concrete Beams Using Bacteria." Materials 15, no. 21 (October 26, 2022): 7506. http://dx.doi.org/10.3390/ma15217506.
Full textAbstract:
Deterioration or crack formation in concrete elements is a phenomenon that cannot be easily avoided, and it has a high cost of repair. A modern technology that needs wider study is the use of the bio-precipitation of calcium carbonate using bacteria to increase a structures’ capacity. The current research presents an analytical study on self-healing concrete beams using bacteria to enhance the beam’s capacity. A Finite Element Analysis on (ANSYS 15.0) was carried out to study the effect of the bacteria concentration (the weight of bacteria to cement weight 1%, 2%, and 3%), the type of bacteria (Bacillus subtilis, E. coli, and Pseudomonas sps.), and the loading (a one-point load, a two-point load, and a distributed load on four points) on concrete beams. Two beams were chosen from previous experimental research and simulated on the ANSYS before carrying out our parametric study to verify the validity of our simulation. Following this, our parametric study was carried out on eight beams; each beam was loaded gradually up to failure. The results show that the optimum type of bacteria was the Bacillus subtilis, and that the bacteria concentration of 3% for Bacillus subtilis can increase the beam’s capacity by 20.2%. Also, we found that distributing the load to four points led to the increase of the beam’s capacity by 74.5% more than the beam with a one-point load.
20
Thilagar, K., and S. Suresh Babu. "Analytical Study on Flexural Behaviour of Light Gauge Steel Corrugated Section Encased in Concrete." Journal of Physics: Conference Series 2040, no. 1 (October 1, 2021): 012026. http://dx.doi.org/10.1088/1742-6596/2040/1/012026.
Full textAbstract:
Abstract Light gauge elements for integrated beams were used, and thin webs are typically needed in constructed beams’ economical design. However, the buckling problem may arise if the Web is fragile. This risk may be reduced by using thicker panels, web reinforcements, or web enhancements. The use of corrugated Web is a possible means of achieving adequate rigidity and shear resistance without hardeners. Analytical studies were conducted in this present work to study the bending behavior of the conventional beam and light-weight steel beam with corrugated, concrete enclosed Web. Analyzes of finite elements have been conducted using the ANSYS beam software. The results present the capacity for load carrying and the deformation of the concrete-covered corrugated web beams. This study’s main objective is to acquire a better knowledge of a concrete embedded steel beam’s behavior.
21
Kamonna, Hayder H. H., Qasim M. Shakir, and Haider A. Al-Tameemi. "Behavior of High-Strength Self-Consolidated Reinforced Concrete T-Deep Beams." Open Construction and Building Technology Journal 14, no. 1 (May 23, 2020): 51–69. http://dx.doi.org/10.2174/1874836802014010051.
Full textAbstract:
Background: When a beam is loaded on two opposite faces and the beam’s depth is increased such that either the span-to-depth ratio is smaller than four or the shear-span-to-depth ratio is less than two, it will behave like a deep beam. Strain distribution in deep beams is different from that of ordinary beams because it is nonlinear along with the beam depth. If the beam is cast monolithically with a slab in the slab–beam system, it is considered a T-deep beam. The behavior of the resulting member is more complicated. Objective: The effect of flange width on the behavior of high-strength self-consolidated reinforced concrete T-deep beams was investigated. Methods: Experimental and numerical studies were conducted. Two shear span-to-depth ratios (1.25 and 0.85) were adopted for two groups. Each group consisted of four specimens: one rectangular beam that served as a reference beam and three flanged beams with flange widths of 440, 660 and 880 mm. All specimens had an overall depth of 450 mm, a width of 160 mm and a total length of 1600 mm. The tests were performed under a two-point load with a clear span of 1400 mm. A nonlinear analysis was also performed using ANSYS software. Results: Throughout the study, the performance of the T-deep beams has been investigated in terms of cracking loads, failure loads, modes of failure, loading history, rate of widening of cracks and ductility index. Results revealed that such parameters have a different ranges of effect on the response of T-deep beams. Calibration of the ANSYS model has been done by comparing results of load-deflection curves, cracking and failure loads with that obtained experimentally. Conclusion: The study’s results indicated that increasing the flange width yielded an 88% improvement in the failure load and an approximately 68% improvement in the cracking load. This positive effect of flange width on the failure load was more pronounced in beams with higher shear span to- depth ratios and flange widths of 660 mm. In addition, the beam’s ductility was improved, especially in cases corresponding to a higher shear span-to-depth ratio. The finite element simulation showed good validation in terms of the load-deflection curve with a maximum failure load difference of 9%. In addition, the influence of longitudinal steel reinforcement on the behavior of such members was studied. Some parameters that reflect the effect of changing the flange width on the behavior of deep beams were also presented. Increasing the flange width is more effective when using normal strength concrete than when using high-strength concrete in terms of cracking load, beam stiffness, and failure load.
22
Viet, N. V., W. Zaki, and Quan Wang. "Free vibration characteristics of sectioned unidirectional/bidirectional functionally graded material cantilever beams based on finite element analysis." Applied Mathematics and Mechanics 41, no. 12 (November 18, 2020): 1787–804. http://dx.doi.org/10.1007/s10483-020-2664-8.
Full textAbstract:
AbstractAdvancements in manufacturing technology, including the rapid development of additive manufacturing (AM), allow the fabrication of complex functionally graded material (FGM) sectioned beams. Portions of these beams may be made from different materials with possibly different gradients of material properties. The present work proposes models to investigate the free vibration of FGM sectioned beams based on one-dimensional (1D) finite element analysis. For this purpose, a sample beam is divided into discrete elements, and the total energy stored in each element during vibration is computed by considering either Timoshenko or Euler-Bernoulli beam theories. Then, Hamilton’s principle is used to derive the equations of motion for the beam. The effects of material properties and dimensions of FGM sections on the beam’s natural frequencies and their corresponding mode shapes are then investigated based on a dynamic Timoshenko model (TM). The presented model is validated by comparison with three-dimensional (3D) finite element simulations of the first three mode shapes of the beam.
23
Shousha, Hoda, Rasha T. S. Mabrouk, and Akram Torkey. "Shear Behavior of Reinforced Concrete Inverted-T Deep Beam." Civil Engineering Journal 9, no. 5 (May 1, 2023): 1059–84. http://dx.doi.org/10.28991/cej-2023-09-05-04.
Full textAbstract:
Contrary to top-loaded deep beams, Inverted-T (IT) deep beams are loaded on ledges at the beam’s bottom chord. The presence of the load near the bottom of the beams creates a tension field in the web at the loading points. An experimental investigation was carried out in which 8 specimens of reinforced concrete IT deep beams were tested and the effect of the following variables was studied: changing the hanger diameter, hanger arrangement in terms of spacing and distribution distance, hanger reinforcement ratio, vertical and horizontal web shear reinforcement diameter, and spacing. In addition, all the tested beams had long ledges extending to the end of the beam. It was concluded that hanger reinforcement diameter and horizontal web shear reinforcement have an insignificant effect on the IT deep beam capacity. While the change in hanger arrangement, vertical web reinforcement, and ledge length has a significant effect on IT deep beam capacity. The maximum spacing of the hanger reinforcement and the minimum hanger reinforcement ratio passing through the load plate length will be studied in the following publication. A finite element model (FEM) was presented to predict the behavior of IT deep beams. The simulation was carried out using the ABAQUS 2017 software program. The results of the numerical model showed good agreement with the experimental program. Analysis using design codes was checked against the experimental data, where the computed beam capacities were compared to those obtained from the test results. The comparison showed a remarkable difference between the predictions using the design codes and the test results. Computation using design codes significantly underestimated the capacities of the beams. Doi: 10.28991/CEJ-2023-09-05-04 Full Text: PDF
24
Song, Cao, Jing Ya Zhou, and Hong Mei Zhang. "Studies on RC Beams Strength with Steel Wires Using Nolinear Finite Element Method." Advanced Materials Research 690-693 (May 2013): 895–99. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.895.
Full textAbstract:
High strength stainless steel wire mesh-polymer mortar reinforcement method was a kind of advanced reinforcement technique.The present study attempted to do a model analysis on the test of the high strength steel wire mesh-polymer mortar reinforcement of less stress beams by using finite element software ANSYS. The study was conducted through the analysis of the three factors of the tested bending reinforcement beam’s deflection, deformation and stress and comparison of the changes of the beam’s ultimate load and failure mode before and after reinforcement.The results of ANSYS analysis and the test showed that the failure mode shifts from less reinforcement damaged into reinforcement destruction;the crack loading value of the reinforced beams increased indicating that the beam bottom reinforcement layer had a significant effect on the increase of the beam’s crack loading. Increased significantly compared to non-reinforced ultimate bearing capacity of reinforced beams. the ANSYS finite element simulation agrees well with the experimental value.
25
Powell, J., R. Joosten, C. A. Donahue, R. F. Fairchild, J. Fujisawa, F. Q. Guo, P. E. Haustein, et al. "BEARS: radioactive ion beams at Berkeley." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 455, no. 2 (December 2000): 452–59. http://dx.doi.org/10.1016/s0168-9002(00)00508-8.
Full text
26
Hawileh, R., Adil K. Al-Tamimi, J. A. Abdalla, and M. H. Wehbi. "Retrofitting Pre-Cracked RC Beams Using CFRP and Epoxy Injections." Key Engineering Materials 471-472 (February 2011): 692–96. http://dx.doi.org/10.4028/www.scientific.net/kem.471-472.692.
Full textAbstract:
The applications of Carbon Fiber Reinforced Polymers (CFRP) in construction have been grown drastically in the last 20 years because of the wide range of advantages and benefits of using CFRP in buildings, bridges and other type of structures. Nowadays, it is used for retrofitting concrete, masonry, steel and timber structures to resist both static and dynamic loads. Since the cost of replacing an existing structure is far more expensive than using FRP materials to strengthen it, CFRP strengthening techniques seem to be cost effective and easy to implement. Numerous experimental and numerical studies have been conducted to investigate the flexural and shear performance of uncracked reinforced concrete (RC) members externally strengthened with CFRP laminates or strips. However, the most practical usage of CFRP is to retrofit sections that had already been cracked and in need of maintenance. The fact that there have been limited studies to investigate the behavior and performance of pre-cracked beams strengthened with CFRP systems necessitated new and further investigations. In this study, the flexural performance of cracked RC beams retrofitted with CFRP plates and epoxy injections are investigated. The results of the cracked beams are compared with two control beams, a virgin un-strengthened beam and an uncracked beam strengthened with a CFRP plate covering 90% of the beam’s span. Load-midspan deflections for these beams were generated and compared. It is observed that the retrofitted cracked beams displayed more strength than the control beam. The results presented herein can aid designers in establishing a better understanding of the flexural performance of pre-cracked beams and how to economically retrofit such structural members.
27
Perry, Roy, and Yuri Lyubarsky. "The role of resonant plasma instabilities in the evolution of blazar-induced pair beams." Monthly Notices of the Royal Astronomical Society 503, no. 2 (February 5, 2021): 2215–28. http://dx.doi.org/10.1093/mnras/stab324.
Full textAbstract:
ABSTRACT The fate of relativistic pair beams produced in the intergalactic medium by very high energy emission from blazars remains controversial in the literature. The possible role of resonance beam plasma instability has been studied both analytically and numerically but no consensus has been reached. In this paper, we thoroughly analyse the development of this type of instability. This analysis takes into account that a highly relativistic beam loses energy only due to interactions with the plasma waves propagating within the opening angle of the beam (we call them parallel waves), whereas excitation of oblique waves results merely in an angular spreading of the beam, which reduces the instability growth rate. For parallel waves, the growth rate is a few times larger than for oblique ones, so they grow faster than oblique waves and drain energy from the beam before it expands. However, the specific property of extragalactic beams is that they are extraordinarily narrow; the opening angle is only Δθ ∼ 10−6 to 10−5. In this case, the width of the resonance for parallel waves, ∝Δθ2, is too small for them to grow in realistic conditions. We perform both analytical estimates and numerical simulations in the quasi-linear regime. These show that for extragalactic beams, the growth of the waves is incapable of taking a significant portion of the beam’s energy. This type of instability could at best lead to an expansion of the beam by some factor but the beam’s energy remains nearly intact.
28
Ma, Gao, Liang Huang, Libo Yan, Hui Wang, and Peng Yin. "Flexural and Thermal Properties of Novel Energy Conservation Slotted Reinforced Concrete Beams." Advances in Materials Science and Engineering 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/4642810.
Full textAbstract:
Conventional solid reinforced concrete (RC) beams were modified to slotted beams for consideration as thermal insulation structural components. The slotted beam consisted of an outer and an inner beam, respectively, with a slot located near the middle of the beam along its width direction for filling thermal insulation material. Flexural and thermal behavior of the slotted beams were investigated. Three RC reference solid beams and six slotted beams were fabricated and tested under four-point bending tests. The test results indicated that the failure mode of both slotted beams and the solid beams was flexural failure. However, the damage process of the slotted beams was different from that of the solid beams at the final loading stage. The moment curvature analysis indicated that the tensile reinforcement ratio of the outer and inner beams had an important effect on the flexural behavior, especially the ductility of the slotted beams. Thermal study indicated that the heat transfer coefficient of the slotted beam was greatly reduced and the thermal inertia factor increased a lot, compared with the solid beam. In addition, FE simulation results showed that a new frame structure using slotted beams exhibited obvious and attractive thermal insulation property.
29
Mohammed, Thaer Jasim, Khalid M. Breesem, and Abeer F. Hussein. "Numerical Analysis of Torsional Reinforcement of Concrete Beams in Unconventional by ANSYS Software." Civil Engineering Journal 9, no. 1 (January 1, 2023): 41–51. http://dx.doi.org/10.28991/cej-2023-09-01-04.
Full textAbstract:
In this study, a finite element analysis is conducted to study the behaviour of RC beams with different configurations of transverse reinforcement under torsion. These configurations of stirrups are traditional closed stirrups, circular spiral stirrups, and inclined rectangular spiral stirrups. The numerical torsional load values are compared with the experimental torsional load values from previous research. The numerical analysis determined by the ANSYS software shows a reasonable agreement with the experimental torsional load values. The numerical results demonstrate that the use of continuous rectangular spiral stirrups improved the torsional response compared to using another type of beam stirrup. Thus, numerical results show that continuous spiral stirrups are effective at increasing torsional capacity. It is also noted that the behaviour of these beams with continuous spiral stirrups is better than the behaviour of the beams with traditional stirrups. The beams with helical reinforcement, which are TB2, TB3, and TB4 spiral reinforcements, greatly enhanced the toughness. The equivalent stresses are 13.709, 13.728, 14.72, and 15.894 MPa, while the equivalent elastic strains are 0.00421, 0.00377, 0.00347, and 0.00539 mm/mm for the beams TB2, TB3, and TB4, respectively. The beam TB4 had the highest stress and strain value, so its strength improved its ductility properties. As a result, the stirrups' configurations enabled the detection of beam failure mechanisms by improving torsional behaviour when compared to the beam's traditional stirrups. As a result, this research adds more knowledge to the literature on the most effective spiral stirrups for transverse reinforcement to improve the torsional behaviour of beams. Doi: 10.28991/CEJ-2023-09-01-04 Full Text: PDF
30
François, Marc L. M., Benoit Semin, and Harold Auradou. "Identification of the Shape of Curvilinear Beams and Fibers." Applied Mechanics and Materials 24-25 (June 2010): 359–64. http://dx.doi.org/10.4028/www.scientific.net/amm.24-25.359.
Full textAbstract:
This work concerns the shape identification of curvilinear objects, for example bent beams or wires in mechanics. The beam’s digital picture is analyzed with the introduced Virtual Image Correlation method. This one consists in finding the optimal correlation between the beam’s image and a virtual beam, whose curvature field is described by a truncated series. The gray level and amplitude of the virtual beam does not need to reproduce exactly the ones of the physical beam image. The analytical form of the optimal shape allows one to derive mechanical properties: the identification of the Young’s modulus of a bar is given as an example. We will also show the robustness of the method with regards to the quality of the image.
31
Atiyah, Qasim A., and Imad A. Abdulsahib. "The Behavior of the Synchronous and Asynchronous Natural Frequencies for Asymmetric Double Beams." Mathematical Modelling of Engineering Problems 9, no. 5 (December 13, 2022): 1243–50. http://dx.doi.org/10.18280/mmep.090511.
Full textAbstract:
The effect of vibrations on asymmetric double beams is a common engineering problem in various engineering applications. In this paper, the synchronous (lower) and asynchronous (higher) natural frequencies of the asymmetric double beams are calculated using the Bernoulli-Euler method. Where the traditional methods are used to find the frequency equations at different boundary conditions, such as Pinned beam, clamped-Clamped beam, Clamped-Free beam, and Clamped-Pinned beam. The increase in the stiffness of the elastic connected layer leads to an increase in the values of the high frequencies of double beams. The greatest effect of changing the thickness of one of the upper or lower beams is for CF beams and the least effect is for CP beams. The length of the beam affects the higher and lower frequencies in high and close proportions for almost all types of beams, and the least effect is only on the higher frequencies of CF beams. The influence of the modulus elasticity change is relatively small on the lower natural frequencies of all types of beams except for CF beams, and its effect is relatively large on the higher natural frequencies of the most types of beams and comparatively less on the CF beams. The effect of varying the values of mass density is relatively small on the low natural frequencies of all types of beams except for CF beams, and its effect is comparatively large on the higher natural frequencies of all types of beams and relatively less on the CF beams.
32
Wang, Zhenai, Tingting Lang, and Yanqing Qiu. "Wideband Airy Beam Generation Using Reflective Metasurfaces with Both Phase and Amplitude Modulation." Photonics 10, no. 4 (April 10, 2023): 426. http://dx.doi.org/10.3390/photonics10040426.
Full textAbstract:
Airy beams are an intriguing type of non-diffraction wave packet that can exist in one-dimensional (1D) curved orbital plane systems. These beams have gained significant attention due to their unique properties, including non-diffraction, self-healing, and self-bending. In this study, we propose a method for generating high-efficiency and wideband Airy beams in microwave sections with reflective geometry, which is challenging to achieve due to the complexity of the Airy beam’s function and generation structure. Our approach involves both phase modulation and amplitude modulation. The designed metasurfaces were numerically simulated to obtain the most significant features of the microwave Airy beam. In addition, they are well in agreement with those predicted by theory.
33
Tarigan, Johannes, Andrew Pakpahan, Medis Surbakti, and Nursyamsi Nursyamsi. "Analysis and experimental usage of CFRP wrap type on flexural strength of concrete beam." MATEC Web of Conferences 258 (2019): 03001. http://dx.doi.org/10.1051/matecconf/201925803001.
Full textAbstract:
Today, reinforced concrete structures are commonly used in buildings because the price cheaper than steel structures. However, many concrete structures are damaged. There are several ways to overcome this problem, and one of them is by strengthening the structure using Fiber Reinforced Polymer (FRP). This study discussed the flexural strength of reinforced concrete beams using Fiber Reinforced Polymer (FRP). In this case, the researchers used Carbon Fiber Reinforced Polymer (CFRP) Wrap Type as the external reinforcement. The beam’s dimension was 15 x 25 cm with a length of 320 cm. Based on the analysis results, the beam using CFRP Wrap type can increase the load 3.12 % times. Furthermore, the experimental results show that the beam with the CFRP type Wrap increases the load by 2.5 times. In conclusion, beams strengthened with CFRP Wrap type can inhibit initial cracks and hold the tensile and flexural strength greater than un-strengthened beams.
34
Du, Chuang, Wen Ling Tian, Xiao Wei Wang, and De Jun Wang. "Experimental Research on Ceramsite Concrete Beams." Applied Mechanics and Materials 166-169 (May 2012): 708–11. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.708.
Full textAbstract:
Six specimens, including 4 ceramsite concrete beams(one of beams mixed into the polypropylene fiber ) and 2 normal concrete beams, were tested to investigate the flexural behavior. The test results show that cracking load of ceramsite concrete beams is slightly smaller than the ordinary concrete beam and cracking load of ceramsite concrete beams has significantly improved after mixing into the polypropylene fibers. The ultimate load of ceramsite concrete beams are no less than ordinary concrete beam,and fibers have not effects on the increase of ultimate load. Load-deflection curves were compared,and the results show that stiffness of ceramsite concrete beam is less than ordinary concrete beam. Ductility of ceramsite concrete beam is poorer than ordinary concrete beam. Fibers improve the stiffness of ceramsite concrete beam. Cover thickness of concrete beam has little effect on the performance of ceramsite concrete beam.
35
Rageh, Basem O., Mahmoud A. El-Mandouh, Ahmed H. Elmasry, and Mohammed M. Attia. "Flexural Behavior of RC Beams Strengthened with GFRP Laminate and Retrofitting with Novelty of Adhesive Material." Buildings 12, no. 9 (September 14, 2022): 1444. http://dx.doi.org/10.3390/buildings12091444.
Full textAbstract:
Two unique approaches were proposed to strengthen the bond between the glass fiber reinforcement polymer (GFRP) and the RC concrete surfaces. The two bonding materials are epoxy (EP) and geopolymer (GPP) with different ratios of short glass fibers (SGF). The experimental program includes seven reinforced concrete (RC) beams that have the same cross-section (150 mm × 200 mm) and are 1500 mm in length. The first beam is the control beam (B0-Control). The next three beams B1-0-GPP, B2-0.6-GPP, and B3-1.2-GPP have GPP with SGF ratios of 0%, 0.6%, and 1.2%, respectively. The last three beams B4-0-EP, B5-0.6-EP, and B6-1.2-EP have EP with SGF ratios of 0%, 0.6%, and 1.2%, respectively. The results show that the failure loads of beams B1-0-GPP, B2-0.60-GPP, and B3-1.2-GPP are greater than the control beam B0-Control by approximately 20.80%, 25.60%, and 31.40%, respectively, whereas the failure loads of beams B4-0-EP, B5-0.6-EP, and B6-1.2-EP are greater than the B0-Control by approximately 16.90%, 26.90%, and 26.10%, respectively; it is also noted that debonding occurs. In addition to the adhesive material, GPP has a great effect on increasing the beam’s failure load capacity due to the enhanced interfacial bond shear strength. Additionally, a finite-element program ABAQUS is performed to verify the experimental results.
36
Tang, Gui He, and Bo Wu. "Fire Behaviors of Restrained RC Beams with Slab." Advanced Materials Research 163-167 (December 2010): 1445–50. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1445.
Full textAbstract:
Using the computer program SAFIR, the behaviors of restrained reinforced concrete (RC) beams with slab exposed to ISO834 standard fire are analyzed. The influences of three parameters (i.e., width of slab, axial restraint stiffness ratio, and rotational restraint stiffness ratio) on the beams’ behaviors in fire are investigated. Simulation results show that: (a) the axial force in the slab is much larger than that in the beam on the whole; (b) after 0.5 hour of heating the axial force in the slab decreases gradually with an increasing of the slab width ranging from 1.0 m to 2.5 m, but the influence of the slab width ranging from 1.0 m to 2.5 m on the axial force in the beam is limited; and (c) the effect of the rotational restraint stiffness ratio on the axial force in the beam/slab is very limited, but the beam’s peak hogging moment increases gradually with an increasing of the rotational restraint stiffness ratio.
37
EL HARTI, Khalid, Rachid SAADANI, and Miloud RAHMOUNE. "Dynamic Control of Non-Linearly Tapering FGM Beams." Eurasia Proceedings of Science Technology Engineering and Mathematics 18 (October 20, 2022): 46–54. http://dx.doi.org/10.55549/epstem.1192327.
Full textAbstract:
This work presents the dynamics and active vibration control of a non-uniform functionally graded beam. Thanks to the strong use of beams and specifically with non-uniform section, in the different industrial applications, such as helicopter rotor blades, wind turbines, space and marine structures, we present in this article, a comparison of linearly and non-linearly tapering beams. The FGM beam is equipped with four layers of piezoelectric materials as sensors and actuators, bonded on the upper and lower surfaces of the main structure, on different finite elements to see the influence of its location on the dynamics and active control. In this study, the Timoshenko beam’s theory combined with FEM is applied to a beam divided into a finite number of elements. Hamilton's principle is applied to generate the equation of motion. The structure is modeled analytically and numerically and the simulation results are presented at the end. The optimal LQG control with Kalman filtering is applied.
38
Reddy, Ch Sandeep, M. Kranthi Kumar, Gandhavalla Madhavarao, Thirumalairaja R, and Manikandan C. "Behavior of Castellated Beams with and Without Stiffeners." International Journal of Innovative Research in Computer Science and Technology 8, no. 5 (September 29, 2020): 394–99. http://dx.doi.org/10.55524/ijircst.2020.8.5.12.
Full textAbstract:
Castellated beam applications for diverse buildings are quickly gaining popularity. This is a result of the section's enhanced depth without adding weight, excellent strength-to-weight ratio, low maintenance requirements, and low cost of painting. Increased vertical bending stiffness, ease of service provision, and appealing appearance are the main advantages of castellated beams. Castellated beams are made by zigzaggingly cutting I sections, then rejoining them to increase the depth of the parent I sections. When castellated beams are loaded, their increased depth makes them more susceptible to web post buckling and lateral torsional buckling failure. There are numerous other forms of failure that must be considered, such as the development of flexure mechanisms, lateral torsional buckling, and vierendeel mechanisms, rupture of the welded joint in a web post, and shear buckling of a web post. A study demonstrates how using stiffeners in the beam's web part can reduce these failures. Therefore, it is necessary to do a thorough analysis of the stiffeners' number, size, and readily available places in the web part of the castellated beam. In order to explore the experimental and analytical behavior of the castellated beam with stiffeners, an attempt has been undertaken in the current paper. The outcome shows that using end stiffeners at the ends of castellated beams increases their strength and reduces their deflection.
39
Permyakov, Gleb, Roman Davlyatshin, Vladimir Belenkiy, Dmitry Trushnikov, Stepan Varushkin, and Pang Shengyong. "Numerical analysis of the process of electron beam additive deposition with vertical feed of wire material." Metal Working and Material Science 24, no. 3 (September 15, 2022): 6–21. http://dx.doi.org/10.17212/1994-6309-2022-24.3-6-21.
Full textAbstract:
Introduction. At present, additive technologies are actively developing all over the world and are becoming more and more widely used in industrial production. The use of electron beams in additive processes of directed energy input, the so-called Directed Energy Deposition (DED) technologies, has several advantages, the main ones being the flexibility of controlling the spatial and energy characteristics of the thermal source and the presence of a vacuum protective environment. The standard scheme for additive electron beam deposition is melting of a wire filler material fed from the side into the electron beam affected area, but this additive electron beam deposition pattern does not provide a uniform thermal impact in the deposited area. The most effective method for electron-beam deposition is vertical wire feeding, which provides the most stable formation of the liquid metal bath and, consequently, the deposited beads. At the same time, so far there are no results of numerical analysis of this process in order to determine its main regularities. The aim of the work is to carry out numerical experiments for qualitative analysis and determination of the regularities of formation of deposited beads and transfer of filler material, the dependence of the geometric characteristics of the obtained beads on the influence of vapor pressure forces, direction and value of the azimuthal angle of heat sources. The research methods were a series of numerical experiments, which analyzed variants of the electron-beam surfacing process at the location of the surfacing rate vector in the action plane of electron beams and perpendicular to this plane to determine the basic regularities of deposited beads formation and transfer of filler material, dependence of geometric characteristics of obtained beads on the influence of vapor pressure forces, direction of heat sources and the azimuth angle of heat sources. Results and discussion. It is found that the geometric characteristics of the deposited beads significantly depend on the relative position of the deposition velocity vector with respect to the plane of the electron beams, and consideration of the vapor pressure has a significant influence on the results of numerical simulation of the weld pool formation and the hydrodynamic processes occurring in it. In this case, the location of the deposition velocity vector perpendicular to the action plane of the electron beams, there is a more uniform geometry of the deposited metal beads, and increasing the azimuthal angle of the heat sources increases the probability of spitting to the periphery of the deposited bead, which is associated with limitation of the melt motion in the longitudinal direction by the vapor pressure forces.
40
Dong, Jiang Feng, Qing Yuan Wang, Ci Chang Qiu, and Dong He. "Experimental Study on RC Beams Strengthened with CFRP Sheets." Advanced Materials Research 213 (February 2011): 548–52. http://dx.doi.org/10.4028/www.scientific.net/amr.213.548.
Full textAbstract:
This paper presents the flexural performance of reinforced concrete (RC) beams with rectangular section. Seven RC beams strengthened using carbon fiber reinforced polymer (CFRP) sheets were subjected to four-point bending to investigate the effect of fiber reinforcement on the beams strengthened. The main experimental parameters included in the study are the pre-cracked width, CFRP sheet layers, the longitudinal tensile reinforcement ratio, the shear span ratio, and the concrete cover thickness. In total, seven beams were cast, one beam without any reinforcement as a control beam, two beams strengthened by CFRP sheets without making pre-cracks on the beam and four pre-cracked beams repaired with one layer or two layers CFRP sheets. Test results show the effectiveness and flexural capacity of the CFRP strengthened beams. The flexure enhancement of the CFRP strengthened beams varied between 41.7% and 124.1% over the control beam. This study confirms that the CFRP reinforcing technique significantly enhances the flexural capacity of reinforced concrete beams.
41
Al-Thabhawee, Hayder Wafi. "Experimental investigation of composite steel–concrete beams using symmetrical and asymmetrical castellated beams." Curved and Layered Structures 9, no. 1 (January 1, 2022): 227–35. http://dx.doi.org/10.1515/cls-2022-0019.
Full textAbstract:
Abstract This study aims to investigate the behavior of concrete slabs acting compositely with symmetrical and asymmetrical castellated beams. Stud connectors are used to connect the concrete slab and steel section. The use of castellated steel beams to build up composite steel-concrete beams is now common practice in building construction. Five simply supported composite beams were examined under two-point loading. Two specimens built up from standard steel beams were used as control specimens and three specimens were built up from castellated steel beams. One of these specimens was built up using a castellated steel beam with an asymmetrical cross-section fabricated from two different standard sections (IPE120/HEA120). The concrete slab of all composite specimens had the same dimensions and properties. The experimental results showed that strength and rigidity were considerably greater for composite castellated steel beams compared to composite beams built up from the parent sections. The ultimate load capacity of a composite castellated beam fabricated from an IPE120 section was 46% greater than that of a composite beam built up using the parent beam, and the ultimate load capacity of a composite castellated beam fabricated from a wide-flanged HEA120 section resulted in an increase of 21% over the parent beam control specimen. The ultimate load capacity of the composite specimen built up using the asymmetrical castellated beam (IPE120/HEA120) achieved increases of 69% and 12%, respectively, compared to the control specimens built up from standard sections.
42
Badawy, Amr H., Ahmed Hassan, Hala El-Kady, and L. M. Abd-El Hafez. "The Behavior of Reinforced and Pre-Stressed Concrete Beams under Elevated Temperature." International Journal of Engineering Research in Africa 47 (March 2020): 15–30. http://dx.doi.org/10.4028/www.scientific.net/jera.47.15.
Full textAbstract:
The behavior of unbounded post tension and reinforced concrete beams under elevated temperature was presented. The experimental work was consisted of two major phases. In the first phase, the objective was studying the mechanical performance of prestressed beam, prestressed beam with steel addition and reinforced concrete beams respectively were studied. In the second phase, the residual mechanical performance of prestressed beam, prestressed beam with steel addition and reinforced concrete beams under elevated 400oC, for 120 minutes durations. The failure mechanisms, ultimate load capacity, and deflection at critical sections were monitored. The numerical prediction of the flexural behavior of the tested specimens is presented in this paper. This includes a comparison between the numerical and experimental test results according to ANSYS models. The results indicate that the prestressed beam with steel addition and reinforced concrete beams had higher resistance to beams under elevated 400oC than that of prestressed concrete beam in terms of ultimate capacity. It is also shown that the reinforced concrete beams have higher resistance to beams under elevated temperature than that of prestressed beam, prestressed beam with steel addition.
43
Jabir, Hussain Askar, Thaar Sauid Salman, and Jasim Mahmood Mhalhal. "Effect of Construction Joints on the Behavior of Reinforced Concrete Beams." Journal of Engineering 23, no. 5 (April 30, 2017): 47–60. http://dx.doi.org/10.31026/j.eng.2017.05.04.
Full textAbstract:
In this study, the effect of construction joints on the performance of reinforced concrete beams was experimentally investigated. Seven beam specimens, with dimensions of 200×100×1000 mm, were fabricated. The variables were considered including; the location and configuration of the joints. One beam was cast without a joint (Reference specimen), two specimens were fabricated with a one horizontal joint located either at tension, or compression zone. The fourthbeam had two horizontal joints placed at tension, and compression area. The remaining specimens were with one or two inclined joints positioned at the shear span or beam’s mid-span. The specimens were subjected to a monotonic central concentrated loading until the failure. The results of the experimental program indicated that the best location of the construction joint is at the compression zone. The presence of the horizontal construction joint at tension zone resultedin a reduction in strength of beams, about 5% - 7.5%, relative to the reference beam. However, the inclined construction joint had a little effect on the collapse load of beams, about 1.25% -2.5%.
44
Guo, Nan, Chao Yang, Ling Li, Guodong Li, and Yan Zhao. "Experimental Study on Flexural Performance of Regulated Reinforced Glulam Beam after Long-Term Loading." Sustainability 13, no. 10 (May 17, 2021): 5556. http://dx.doi.org/10.3390/su13105556.
Full textAbstract:
Due to wood creep characteristics, the failure mode, bearing capacity, stiffness, and deformation of its components are doomed to be impacted by long-term loading. This paper conducted a comparative test on creep beams, regulated beams, and short-term beams based on the former long-term loading research. The results demonstrated that the glulam beam experienced tensile failure of the beam-bottom, while the horizontal joint failure and the local compressive failure of the beam-end happened in the reinforced glulam beam and the prestressed glulam beam. The bearing capacity of the creep beams decreased compared with that of the short-term beams; the decline in the bearing capacity of the ordinary glulam beams, the reinforced glulam beams, and the prestressed glulam beams ranged from 3.2% to 9.8%, from 1.6% to 13.2%, and from 2.9% to 9.2%, respectively. However, the bearing capacity of the regulated beam with the deformation restored to the initial value of the load increased by 4.6–14.1%. The prestressed regulation changed the distribution of the stress on the beam and thus enhanced its bearing capacity. The findings of this work could be used as a frame of reference for similar components in engineering applications.
45
Naidu, G. Ganesh, Soundarya Kasukurthi, Kota Sai Manohar, Adaikkalakumar P, and Chandramouly Y. J. "A Study on Castellated Beams with and Without Stiffeners." International Journal of Innovative Research in Engineering and Management 7, no. 6 (November 20, 2020): 96–101. http://dx.doi.org/10.55524/ijirem.2020.7.6.6.
Full textAbstract:
The use of castellated beams in many types of constructions is quickly gaining popularity. This is a result of the section's enhanced depth without adding weight, excellent strength-to-weight ratio, low maintenance requirements, and low cost of painting. Increased vertical bending stiffness, ease of service provision, and appealing appearance are the main advantages of castellated beams. Castellated beams are made by zigzagging cutting I sections, then re-joining them to increase the depth of the parent I sections. When castellated beams are loaded, their increased depth makes them more susceptible to web post buckling and lateral torsional buckling failure. There are numerous other forms of failure that must be considered, such as the development of flexure mechanisms, lateral torsional buckling, and vierendeel mechanisms, rupture of the welded joint in a web post, and shear buckling of a web post. A study demonstrates how using stiffeners in the beam's web part can reduce these failures. As a result, a thorough analysis of the stiffeners' quantity, size, and readily available positions in the castellated beam's web part is required. In order to explore the experimental and analytical behaviour of the castellated beam with stiffeners, an attempt has been undertaken in the current paper.The result indicates that use of end stiffeners at end portion of castellated beams helps in increasing the strength and also minimizing the deflection.
46
Yu, Lei, Yi Che, Xin Feng Zheng, Jin Xin Gong, and Yu Pu Song. "Effect of Beam Depth and Longitudinal Reinforcement Ratio on Shear Strength of RC Beams." Advanced Materials Research 163-167 (December 2010): 1460–65. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1460.
Full textAbstract:
Seven beams were tested to investigate the effects of beam depth and longitudinal reinforcement ratio on the shear strength of reinforced concrete beams. To investigate the effects of beam depth on shear strength, beams of five different sizes were tested. Two beams were designed to investigate the shear behaviour of beams with small percentage of longitudinal reinforcement. In addition to an experimental investigation, a survey of data in the literature was performed to gain insight into the influence of beam depth and longitudinal reinforcement ratio. Based on test results and a data analysis, conclusions regarding the influence of beam depth and longitudinal reinforcement ratio on shear strength of reinforced concrete beams are presented herein.
47
Seybert, A. F., and P. J. Bowles. "The Radiation of Sound from Mass-Loaded and Stiffened Beams." Journal of Vibration and Acoustics 107, no. 1 (January 1, 1985): 67–73. http://dx.doi.org/10.1115/1.3274718.
Full textAbstract:
This study examines the sound radiation efficiency of uniform, mass-loaded, and stiffened beams. The radiation efficiency of vibrating beams is determined using a finite element vibration model of the beam and a numerical approach to determine the radiated sound field. The radiation efficiency of mass-loaded and stiffened beams deviates from that of the uniform beam for frequencies near and below coincidence. The radiation efficiency of the nonuniform beams depends on the change in natural frequency and the distortion of the mode shape of the vibrating beam. Near coincidence, the radiation efficiency of nonuniform beams approaches that of the uniform beam. Above coincidence, all beams exhibit a radiation efficiency of unity.
48
Bai, Quan, Ke Xiang Wei, and Wen Ming Zhang. "Dynamic Analysis of Sandwich Beams Filled with ER Elastomers." Applied Mechanics and Materials 50-51 (February 2011): 843–48. http://dx.doi.org/10.4028/www.scientific.net/amm.50-51.843.
Full textAbstract:
Considered electrorheological (ER) elastomers as the visco-elasticity material, a finite element model of a sandwich beam filled with ER elastomers was developed based on Hamilton’s principle and sandwich beam’s theory. Then its dynamic characteristics were analyzed. Simulation results show that natural frequencies of the sandwich beam increase and vibration amplitudes of the beam decrease as the intensity of applied electric field increases. Increased the thickness of the ER elastomers layer, natural frequencies of the beam decrease and loss factors increase. Those indicate that the dynamic characteristic of ER elastomers sandwich beams is similar as that of ER fluids beam, which can be used for vibration control of flexible structures by applied a electric field.
49
Luo, Tao. "Research on Mechanical Behavior of RC Beams Strengthened with CFRP by Anti-Arch Method." Applied Mechanics and Materials 578-579 (July 2014): 127–30. http://dx.doi.org/10.4028/www.scientific.net/amm.578-579.127.
Full textAbstract:
The mechanical behavior of RC beam strengthened with CFRP by anti-arch method and directly pasting CFRP through model test is analyzed. It explains that the reinforced RC beam with CFRP by anti-arch method can solve the influence of beam's loading by the secondary stress which exists in the method of pasting CFRP directly in strengthening RC beams improve the beam's load when it cracks and the carrying capacity, and decrease the deflection deformation and crack width and gap when the beam carries load. It can make the most use of high strength of tensile properties of CFRP.
50
A. Yusof and A. L. Saleh. "Flexural Strengthening of Timber Beams Using Glass Fibre Reinforced Polymer." Electronic Journal of Structural Engineering 10 (January 1, 2010): 45–56. http://dx.doi.org/10.56748/ejse.10124.
Full textAbstract:
This research was conducted to investigate the bending behavior of timber beams strengthened with glass fibre reinforced polymer (GFRP) rods. Seven timber beams of Yellow Meranti species with the dimensions of 100 × 200 × 3000 mm were tested. One of the beams was used as a control beam (unstrengthened) while the remaining six beams were strengthened before tested to failure under four point loading. The bending behavior of the beams was studied through their load-deflection characteristics and strain distributionacross the depth of the beam upon loading and also the failure modes. The results showed that the strengthened beams performed better than the control beam. The ultimate load has increased between 20 - 30% for the strengthened beams when compared to the control beam. The stiffness increased between 24 - 60% for the strengthened beams. The beam is categorized as under-reinforced, balance- reinforced, and overreinforced if the percentage of GFRP rod is less than 0.32%, between 0.32 - 0.35%, and greater than 0.35%,respectively. GFRP rod bonding system has a good potential to be used in the new construction or rehabilitation process of timber structures.