Journal articles: 'Prestressed concrete beams Computer programs'

1

Wang, Xiao Dong, Wen Zhong Zheng, and Ying Wang. "Research on Stress Increase of Unbonded Tendons at Ultimate in Prestressed Concrete Continuous Beams." Applied Mechanics and Materials 166-169 (May 2012): 1554–57. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.1554.

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Rational evaluation for stress increase of unbonded tendon at ultimate is the basis to exactly compute flexural load bearing capacity of unbonded prestressed concrete beams. Moment-curvature nonlinear analysis method is adopted to compile programs for calculating stress increase at ultimate in unbonded prestressed continuous beams. The precision of the method is proved by comparing results of 16 experimental two-span unbonded prestressed continuous beams to the prediction value of stress increase at ultimate. Based on the simulation analysis, law of the influence of some basic factors to stress increase at ultimate in unbonded tendons in continuous beams is obtained, such as non-prestressed reinforcement index, prestressed reinforcement index, ratio of span to depth and loading type. Then formulas for calculating stress increase at ultimate in unbonded tendons in prestressed concrete continuous beams were established.

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WILLIAMS, ROM, A. C. CASSELL, and L. F. BOSWELL. "A COMPUTER DESIGN AID FOR PRESTRESSED CONCRETE BOX BEAMS." Proceedings of the Institution of Civil Engineers - Structures and Buildings 94, no. 1 (February 1992): 61–72. http://dx.doi.org/10.1680/istbu.1992.18144.

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Erbatur, F., R. Al Zaid, and N. A. Dahman. "Optimization and sensitivity of prestressed concrete beams." Computers & Structures 45, no. 5-6 (December 1992): 881–86. http://dx.doi.org/10.1016/0045-7949(92)90046-3.

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Tej, Petr, Jiří Kolísko, Petr Bouška, Miroslav Vokáč, and Jindřich Čech. "Prestressed I-Beams Made of Ultra-High Performance Concrete for Construction of Railway Bridges." Applied Mechanics and Materials 578-579 (July 2014): 776–78. http://dx.doi.org/10.4028/www.scientific.net/amm.578-579.776.

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This paper focuses on research into prestressed I-beams made of ultra-high-performance concrete, which are designed to be structural elements in small and medium span railway bridges. Prestressed concrete I-beams are designed with ten prestressing cables in the bottom flange. The prestressed beams are laid close together in the actual structure with panels inserted between them. The entire structure will subsequently become monolithic. At the present time, I-beams made of rolled steel are commonly used as structural elements in this type of structure. The advantage of these types of structures lies in their having a low construction height. This paper presents a computer and experimental analysis of the loading of UHPC prestressed I-beams. For the purpose of the experiments, several specimens of 7 m span were made. The specimens were subsequently tested in the laboratory in four-point bending tests. The paper presents the process and results of the experiments. Simultaneously with the experiments, computer analyses were created in which optimization of the material and geometric parameters of the beams were carried out. The paper demonstrates the correspondence of the experimental and computer-simulated load test results.

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Du, Huanhuan, Jianyou Pan, Huaxun Shen, and Jie Dong. "Numerical Analysis of Flexural Behavior of Prestressed Steel-Concrete Continuous Composite Beams Based on BP Neural Network." Computational Intelligence and Neuroscience 2022 (May 10, 2022): 1–10. http://dx.doi.org/10.1155/2022/5501610.

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Prestressed steel-concrete continuous composite beam (PCCB) is a kind of beam, which makes reinforced concrete slab and steel beam bear load and coordinate deformation through connectors such as studs. Prestressed steel-concrete continuous composite beam is a kind of transverse load-bearing composite member formed by prestressed technology on the basis of ordinary composite beam. Aiming at the flexural behavior of prestressed steel-concrete continuous composite beams, a three-dimensional finite element numerical analysis model is established, and the whole process of the test is simulated based on BP neural network. The calculated results are in good agreement with the test. Using this model, the mechanical deformation performance of prestressed steel-concrete continuous composite beam is further analyzed, and the effects of some parameters (steel beam strength grade, concrete strength grade, concrete slab thickness, and transverse reinforcement ratio) on the flexural performance of prestressed steel-concrete continuous composite beam are discussed, which provides a reference basis for engineering design.

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Elbadry, Mamdouh M., and Amin Ghali. "Analysis of time-dependent effects in concrete structures using conventional linear computer programs." Canadian Journal of Civil Engineering 28, no. 2 (April 1, 2001): 190–200. http://dx.doi.org/10.1139/l00-093.

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Analysis of the time-dependent changes in displacements, internal forces, and reactions at the supports in continuous reinforced concrete structures cast, prestressed, and loaded at different stages is frequently needed in design to satisfy the serviceability requirements. The time-dependent parameters considered in the analysis are creep and shrinkage of concrete, relaxation of prestressed steel, sequence of construction, and changes in structural system and support conditions. A procedure of analysis is presented using conventional linear analysis computer programs. The analysis procedure is explained through examples to demonstrate its simplicity and applicability.Key words: analysis, computer program, creep, displacement, frames, precast concrete, prestressed concrete, relaxation, shrinkage, time-dependent.

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WILLIAMS, R. O. M., A. C. CASSELL, L. F. BOSWELL, and P. WALDRON. "DISCUSSION. A COMPUTER DESIGN AID FOR PRESTRESSED CONCRETE BOX BEAMS." Proceedings of the Institution of Civil Engineers - Structures and Buildings 99, no. 2 (May 1993): 237–38. http://dx.doi.org/10.1680/istbu.1993.23382.

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Pisani, Marco Andrea, Maria Pina Limongelli, Pier Francesco Giordano, and Mattia Palermo. "On the Effectiveness of Vibration-Based Monitoring for Integrity Management of Prestressed Structures." Infrastructures 6, no. 12 (December 3, 2021): 171. http://dx.doi.org/10.3390/infrastructures6120171.

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In this paper, the effectiveness of vibration-based tests for the detection of damages for prestressed concrete beams is investigated. Despite large research efforts, discrepant and sometimes contradicting conclusions have been drawn regarding the efficacy and reliability of vibration-based monitoring for prestressed structures. Herein, a contribution to this discussion is provided by tackling the problem from a different perspective. Specifically, the question that this paper intends to answer is: “Do vibration-based tests support decision-makers in integrity management operations for prestressed elements?” The discussion is carried out by comparing the performance of prestressed and ordinary reinforced concrete beams with similar capacities. Both analytical and numerical case studies are considered. Results show that, for prestressed beams, in contrast to reinforced concrete beams, modal parameters can provide information regarding damage only when the structure is close to its ultimate conditions. This makes this information hardly useful for integrity management purposes and the effectiveness of vibration-based tests questionable for this type of structural element.

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9

Franchetti, P., C. Modena, and M. Q. Feng. "Nonlinear Damping Identification in Precast Prestressed Reinforced Concrete Beams." Computer-Aided Civil and Infrastructure Engineering 24, no. 8 (November 2009): 577–92. http://dx.doi.org/10.1111/j.1467-8667.2009.00612.x.

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10

Tej, Petr, Jiří Kolísko, Petr Bouška, Miroslav Vokáč, and Jindřich Čech. "Prestressed I-Beams of 12 m Span Made of Ultra-High Performance Concrete for Construction of Railway Bridges." Applied Mechanics and Materials 587-589 (July 2014): 1593–96. http://dx.doi.org/10.4028/www.scientific.net/amm.587-589.1593.

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This paper focuses on research of prestressed I-beams made of ultra-high performance concrete (UHPC), which are designed to be structural elements in small and medium span railway bridges. Prestressed concrete I-beams are designed with ten prestressing cables in the bottom flange. The prestressed beams are laid close together in the actual structure, with panels inserted between them. The entire structure will subsequently become monolithic. At the present time, I-beams made of rolled steel are commonly used as structural elements in this type of structure. The advantage of these types of structures lies in their having low construction height. This paper presents a computer and experimental analysis of loading of UHPC prestressed I-beams. For the purpose of the experiments, three specimens of 12 m span were made. The specimens were subsequently tested in the laboratory in four-point bending tests. The paper presents the process and results of the experiments. Simultaneously with the experiments, computer analyses were created in which optimization of the material and geometric parameters of the beams were carried out. The paper demonstrates the correspondence of the experimental and computer-simulated load test results.

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11

Bai, Chong Xi, Xin Yan Shao, and Qiu Ping Wang. "Calculation Methods of CFRP Tendons Stress in Two-Span Prestressed Continuous Beams." Advanced Materials Research 859 (December 2013): 60–63. http://dx.doi.org/10.4028/www.scientific.net/amr.859.60.

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Crack width, deflection and load bearing capacity of two-span concrete continuous beams partially prestressed with unbonded carbon fiber reinforced polymer (CFRP) tendons can be calculated accurately, the first premise is to calculate reasonably the stress increment of CFRP tendons. However, the law of stress increment of unbonded tendons is unclear. Moment-curvature analysis method and deformation compatibility condition were used to compile nonlinear full-range analysis programs of this kind of continuous beam. The comparison between simulated results and tested results of stress in CFRP tendons indicates that the simulation analysis programs are reliable.

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12

Huo, Jun Hua, and Bo Pang. "Mechanical Property Study of Corroded Steel Beams Strengthened with Prestressed CFRP Sheets." Advanced Materials Research 594-597 (November 2012): 955–58. http://dx.doi.org/10.4028/www.scientific.net/amr.594-597.955.

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Steel structure, which has higher bearing capacity, smaller sectional dimension, convenient construction and economical investment, can be abroad used in engineering. However, due to a lot of reasons, the gradual expansion and convergence of the micro-defects lead to the macro deterioration of the mechanical properties of materials. By experimental research, theoretical analysis and computer simulation, the mechanical properties of the corroded steel beams strengthened with (prestressed) CFRP sheets were studied. According to the mechanical characteristics of corrosive steel beams and corrosive composite steel-concrete beams strengthened with prestressed CFRP sheets. By using ABAQUS finite element program, the calculation model of prestressed CFRP sheets strengthened corrosion steel beams and corrosion steel-concrete composite beams is established, and the working mechanism is studied. The calculation results show that: the bearing capacity of strengthened beams increase with the increasing of the initial prestress and CFRP sheets thickness, and decrease with the increase of steel corrosion degrees.

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13

Bai, Chong Xi, Xin Yan Shao, and Qiu Ping Wang. "Stress of Carbon Fiber Reinforced Polymer Tendons in Prestressed Simply Supported Beams." Advanced Materials Research 689 (May 2013): 353–57. http://dx.doi.org/10.4028/www.scientific.net/amr.689.353.

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The law of stress increment of unbonded carbon fiber reinforced polymer (CFRP) tendons at service stage and flexural load bearing capacity limit state is unclear, so it is difficult to accurately calculate crack width, deflection and load bearing capacity. In order to calculate the stress of CFRP tendons, deformation compatibility condition and moment-curvature analysis method are used to compile nonlinear full-range analysis programs of simply supported concrete beam partially prestressed with unbonded CFRP tendons. The computing results of stress in CFRP tendons are in good agreement with the tested results as a whole, so it indicates that the simulation analysis programs are reliable.

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14

Barakat, Samer, Nabil Kallas, and Mohammed Q. Taha. "Single objective reliability-based optimization of prestressed concrete beams." Computers & Structures 81, no. 26-27 (October 2003): 2501–12. http://dx.doi.org/10.1016/s0045-7949(03)00305-5.

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15

Quaranta, Giuseppe, Alessandra Fiore, and Giuseppe Carlo Marano. "Optimum design of prestressed concrete beams using constrained differential evolution algorithm." Structural and Multidisciplinary Optimization 49, no. 3 (August 9, 2013): 441–53. http://dx.doi.org/10.1007/s00158-013-0979-5.

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16

Jinan L. Abbas. "Nonlinear Analysis of Reinforced Concrete Beams Strengthened with Prestressed CFRP sheets Under Cyclic Load." Diyala Journal of Engineering Sciences 5, no. 1 (June 1, 2012): 117–37. http://dx.doi.org/10.24237/djes.2012.05110.

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Analysis of reinforced concrete beams strengthened by prestressed CFRP sheets has been investigated in this paper. A three dimensional finite element analysis ANSYS computer program (version 9.0) was conducted to obtain the response of the strengthened beams. The eight –node brick elements(solid 65) are used for the idealization of concrete while the CFRP sheets are idealized by using three-dimensional layered elements (solid 46).The steel plates are idealized by using three dimensional solid elements (solid 45).Five beams are analyzed in study ,four with prestressed –CFRP sheets and one with non-prestressed- CFRP sheet. The effect of different level of prestress ,induced by prestressing the CFRP –sheets, on the cracking loads and flexural stiffness of the strengthened beams are studied. It is found that the cracking load and the flexural stiffness are significantly increased as the level of prestress increased. The response of the strengthened beam under cyclic loads is also conducted in terms of deflection versus number of cycles which is related to the cyclic behaviour of the constituent materials used in the beam ( concrete , tension steel, and CFRP sheets). The deformation of each these materials under cyclic loadings is presented in terms of measured strains as a percent of the number of cycles of fatigue. The results obtained from finite element analysis are compared with available experimental results and the comparison gives good accuracy

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17

Han, S. H., A. Adamu, and B. L. Karihaloo. "Minimum cost design of multispan partially prestressed concrete T-beams using DCOC." Structural Optimization 12, no. 2-3 (October 1996): 75–86. http://dx.doi.org/10.1007/bf01196938.

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18

Mavaddat, Shahbaz, and M. Saeed Mirza. "Computer analysis of thin-walled concrete box beams." Canadian Journal of Civil Engineering 16, no. 6 (December 1, 1989): 902–9. http://dx.doi.org/10.1139/l89-133.

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Three computer programs, written in FORTRAN WATFIV, are developed to analyze straight, monolithically cast, symmetric concrete box beams with one, two, or three cells and side cantilevers over a simple span or over two spans with symmetric mid-span loadings. The analysis, based on Maisel's formulation, is performed in three stages. First, the structure is idealized as a beam and the normal and shear stresses are calculated using the simple bending theory and St-Venant's theory of torsion. The secondary stresses arising from torsional and distortional warping and shear lag are calculated in the second and third stages, respectively. The execution times on an AMDAHL 580 system are 0.02, 0.93, and 0.25 s for the three programs, respectively. The stresses arising in each stage of analysis are then superposed to determine the overall response of the box section to the applied loading. The results are compared with Maisel's hand calculations. Key words: bending, bimoment, box beam, computer analysis, FORTRAN, shear, shear lag, thin-walled section, torsion, torsional and distortional warping.

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19

Aziz, Mohamad Abdel, George Abdel-Sayed, Faouzi Ghrib, Nabil F. Grace, and Murty K. S. Madugula. "Analysis of concrete beams prestressed and post-tensioned with externally unbonded carbon fiber reinforced polymer tendons." Canadian Journal of Civil Engineering 32, no. 6 (December 1, 2005): 1138–51. http://dx.doi.org/10.1139/l05-071.

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Fiber reinforced polymer (FRP) tendons are being increasingly used nowadays in prestressing and (or) post-tensioning concrete structures. However, designers are faced with lack of practical analysis procedure that leads to proper evaluation of their structural performance, especially when bonded prestressing is combined with unbonded post-tensioning. This paper presents an analytical procedure for these beams. It examines the load–defelction characteristics and proceeds to estimate the ultimate load carrying capacity by taking into consideration the change of stress that occurs in the externally unbonded tendons during different stages of loading. The analytical procedure uses the concept of effective moment of inertia of concrete beams. The equations used are developed by ACI Committee 440, the Intelligent Sensing for Innovative Structures (ISIS) Canada Research Network, and the Comité Euro-International du Béton - Fédération International de la Précontrainte (CEB-FIP), for calculating the deflection of beams reinforced with carbon fiber reinforced polymer (CFRP) tendons. Finite element analyses have been conducted to verify the proposed analytical method. Two experimental programs were used to validate the proposed analytical method. The experimental findings of two box beams reinforced with bonded and unbonded external tendons are compared with finite element analyses and the analytical results. A full-scale test for an internally and externally prestressed double-T beam was undertaken at Construction Technology Laboratories Inc., Skokie, Illinois. The results from this experimental work were used to validate the analytical procedure.Key words: bonded CFRP tendons, concrete, post-tensioning, unbonded CFRP tendons.

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20

Jia, Li, Zhi Fang, Zhengmeng Huang, Kypros Pilakoutas, Qiwu Wang, and Xingyu Tan. "Flexural Behavior of UHPC Beams Prestressed with External CFRP Tendons." Applied Sciences 11, no. 19 (October 2, 2021): 9189. http://dx.doi.org/10.3390/app11199189.

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This paper presents an experimental investigation on the flexural behavior of ultra-high-performance concrete (UHPC) beams prestressed with external carbon fiber-reinforced polymer (CFRP) tendons. A total of eight T-shaped beam specimens were fabricated and tested, and the effects of the effective prestressing stress, partial prestressing ratio, deviated angle, and loading condition on the flexural behavior were analyzed. The experimental results indicate that the fully prestressed beams experienced a brittle failure, and the shear capacity of these beams was mainly controlled by the effective prestressing stress in CFRP tendons and the ultimate tensile strength of UHPC, whereas the partially prestressed beams failed in a ductile manner. The presence of internal steel reinforcement could significantly improve the flexural capacity and deformation ability. Thus, internal reinforcements should not be omitted from UHPC beams with CFRP tendons. A higher effective prestressing stress resulted in enhanced cracking load and flexural capacity. The deviated angle enhanced the utilization efficiency of high strength CFRP tendons. The loading condition exerted a slight influence on the flexural behavior of the specimens. Moreover, a method considering the effect of steel fibers was proposed and verified to predict the flexural capacity of UHPC beams prestressed with external CFRP tendons.

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HAN, S. H., A. ADAMU, and B. L. KARIHALOO. "MINIMUM COST DESIGN OF MULTISPAN PARTIALLY PRESTRESSED CONCRETE BEAMS USING DCOC." Engineering Optimization 26, no. 1 (April 1996): 35–59. http://dx.doi.org/10.1080/03052159608941109.

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22

Nikulina, Y. "DETERMINATION OF CRACK RESISTANCE OF PRESTRESSED REINFORCED CONCRETE BEAMS OF TRAPEZOIDAL CROSS-SECTION." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 6, no. 11 (August 18, 2021): 41–48. http://dx.doi.org/10.34031/2071-7318-2021-6-11-41-48.

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Beams of a trapezoidal cross-section with a wide upper edge with prestressed reinforcement combine positive qualities in terms of strength, crack resistance, deformability and resource saving, which allows them to cover significant spans of multi-storey buildings. To develop a method for calculating the moment of cracking in these structures, a nonlinear deformation model was adopted, which includes equilibrium equations, conditions for the linear distribution of relative deformations along the height of the element section, and refined deformation diagrams of concrete and reinforcement. Concrete state diagrams are assumed to be nonlinear without a falling branch. To describe the deformation diagrams of high-strength and conventional reinforcement, a universal dependence is adopted, consisting of one linear and two nonlinear equations, in which the calculation of individual parameters is performed using different formulas. For the initial stage of the crack formation process, a design scheme is presented, in accordance with which the necessary equations and ratios are drawn up in relation to the considered prestressed reinforced concrete beam of a trapezoidal cross-section. The purpose of the study, in addition to developing a calculation methodology, was also the development of an algorithm and a computer calculation program. To obtain and analyze the results, a numerical experiment was carried out, the results of which are presented in tabular form. Due to the fact that the calculation method was built without involving empirical dependencies, the possibility of its application to determine the crack resistance of prestressed reinforced concrete beams of trapezoidal cross-section for any class of concrete and reinforcement was confirmed.

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23

Husain, Husain M., Nazar K. Oukaili, and Hakim S. Muhammed. "Nonlinear Analysis of CFRP- Prestressed Concrete Beams Subjected to Incremental Static Loading by Finite Elements." Tikrit Journal of Engineering Sciences 15, no. 1 (March 31, 2008): 30–51. http://dx.doi.org/10.25130/tjes.15.1.03.

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In this work a program is developed to carry out the nonlinear analysis (material nonlinearity) of prestressed concrete beams using tendons of carbon fiber reinforced polymer (CFRP) instead of steel. The properties of this material include high strength, light weight, and insusceptibility to corrosion and magnetism. This material is still under investigation, therefore it needs continuous work to make it beneficial in concrete design. Four beams which are tested experimentally by Yan et al. are examined by the developed computer program to reach a certain analytical approach of the design and analysis of such beams because there is no available restrictions or recommendations covering this material in the codes. The program uses the finite element analysis by dividing the beams into isoparametric 20-noded brick elements. The results obtained are good in comparison with experimental results.

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24

Jeyasehar, C. Antony, and K. Sumangala. "Damage assessment of prestressed concrete beams using artificial neural network (ANN) approach." Computers & Structures 84, no. 26-27 (October 2006): 1709–18. http://dx.doi.org/10.1016/j.compstruc.2006.03.005.

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25

Saqan, Elias, and Hayder Rasheed. "Simplified nonlinear analysis to compute neutral axis depth in prestressed concrete rectangular beams." Journal of the Franklin Institute 348, no. 7 (September 2011): 1588–604. http://dx.doi.org/10.1016/j.jfranklin.2010.09.005.

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26

Jian, Zhang, Jia Chao, and Tian Jiawei. "Nonlinear Performance of Concrete Beam Reinforced with Prestressed Hybrid Cfrp/Gfrp Composite Sheet." Advanced Composites Letters 27, no. 5 (September 2018): 096369351802700. http://dx.doi.org/10.1177/096369351802700505.

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The consolidation technology of prestressed hybrid fibre CFRP/GFRP sheet takes full advantages of the initiative of the prestressed reinforcement and force transferring of the composite materials features, which belongs to relatively advanced reinforcement strategies in reinforcement area. This paper derives nonlinear composite element and shell element to simulate concrete beam and the prestressed hybrid fibre CFRP/GFRP sheet. Besides, the characters of nonlinear concrete beams are described by the Owen yielding criterion and the Hinton crushing criterion. Meanwhile, the three-dimensional prestressing effects of the composite CFRP/GFRP materials have been realized and the nonlinear finite element computer program of reinforced system has been compiled. In order to determine the best stress condition of prestressed hybrid fibre CFRP/GFRP composite materials, the optimal hybrid CFRP/GFRP ratio is achieved through the systematic calculation based on two main properties which take the strength and ductility properties into consideration. The results show that the optimal CFRP/GFRP hybrid ratio is one of the major factors to impact its mechanical properties of the reinforced structure which has been strengthened by the prestressed hybrid fibre CFRP/GFRP sheet. And the theoretical method and calculation model that determine the optimal hybrid CFRP/GFRP ratio in this paper is reasonable and reliable. The research conclusions can be used as a reference in practice construction design.

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Yeon, Yeong-Mo, Wookjin Lee, and Ki-Nam Hong. "Finite Element Analysis of Reinforced Concrete Beams Prestressed by Fe-Based Shape Memory Alloy Bars." Applied Sciences 12, no. 7 (March 23, 2022): 3255. http://dx.doi.org/10.3390/app12073255.

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Prestressing of concrete structures using Fe-based shape memory alloys has been investigated extensively by experiments in the last decade. However, detailed investigations on the stress produced by the Fe-based shape memory alloys and its influence on concrete damage during deformation of concrete structure has not been investigated yet. In this study, the prestressing effect by Fe-based shape memory alloy bars on bending behavior of reinforced concrete beam was investigated numerically. A finite element simulation model was developed to investigated the bending responses of the beams including nonlinear material properties such as concrete cracking and crushing as well as the plastic deformation of the Fe-based shape memory alloy. The model is able to capture the bending behavior of the beam prestressed with the Fe-based shape memory alloy bars. Based on the numerical and experimental results, the prestressing effect by the shape memory alloy bars was investigated in detail. Although the developed model slightly overestimated the experimentally obtained bending load-deflection curves of the concrete beams, it was shown that the developed model can be used for an optimization study to select the best possible design parameters for prestressing the concrete beam with the Fe-based shape memory alloy bars. A possible reason for the overestimation is the idealized perfect bonding assumption between Fe-SMA and concrete used in the model, while slip at the interface occurred in the experiments.

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Yan, Wutong, Liangjiang Chen, Bing Han, Huibing Xie, and Yue Sun. "Flexural Analysis Model of Externally Prestressed Steel-Concrete Composite Beam with Nonlinear Interfacial Connection." Applied Sciences 12, no. 9 (May 7, 2022): 4699. http://dx.doi.org/10.3390/app12094699.

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Interfacial slip effects and the unbonded phenomenon of external tendons are the key mechanical features of the externally prestressed steel-concrete composite beams (EPCBs). In this paper, an 8-node fiber beam element is built for the nonlinear analysis of the composite beam with interfacial slip effects. A multi-node slipping cable element is proposed for the simulation of external tendons. The derived formulations are programmed in OpenSees as newly developed element classes to be conveniently used for the flexural analysis of EPCBs. The effectiveness of the proposed model is fully verified against the experimental tests of simply supported and continuous beams and then applied to the parametric study. The results show that the increasing deviator spacing will significantly decrease the tendon effective depth at ultimate states and further decrease the flexural capacity. The larger effective depth is beneficial to the tendon stress increments and further improves the flexural capacity. The enhancement of interfacial shear connection degree will increase the structural capacity but the effects on the tendon stress increments and second-order effects were not monotonic.

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Batchelor, B. deV, and Jayanth Srinivasan. "Calculation of stress in prestressing steel at ultimate conditions." Canadian Journal of Civil Engineering 16, no. 4 (August 1, 1989): 576–82. http://dx.doi.org/10.1139/l89-088.

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This paper reviews different methods available for the calculation of stress in prestressing steel at ultimate, ƒps, and the methods are evaluated using a nonlinear analysis computer program. The development of a nonlinear model for the analysis of partially prestressed concrete flexural members is described. The model takes the material nonlinearities into account by the use of appropriate stress–strain relationships for steel and concrete. A parametric study of partially prestressed beams was conducted to study the effect of various parameters on stress in prestressing steel at ultimate conditions. Two types of sections, rectangular and T sections, were studied. The prediction equation, recommended in the Canadian Code Can3-A23.3-M84, for calculating the stress in prestressing steel at ultimate is found to be very conservative for all the cases studied, which covered all possible ranges of partial prestressing ratio. The present restriction in the Canadian Code, for the use of their prediction equation only when the ratio of the neutral axis depth, Cu, to the depth of the centroid of prestressing steel, dps, is less than or equal to 0.3, is found to be too restrictive. An alternative equation for ƒps, suggested by Loov, is found to be more suitable than the present equation in the Canadian Code; however, a more practical upper limit for cu/dps ratio is suggested in the paper. It is shown that the proposed equation can be used conservatively over the complete range of partially prestressed concrete. Key words: analysis, concrete (prestress), flexure, partial prestressing, prestressing, strain, stress, steel.

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Yang, Chun, Ming Ji He, Jian Cai, Yan Sheng Huang, and Yi Wu. "Study on Mechanical Behaviors and Calculation of Shear Strength of Steel Truss Reinforced Concrete Deep Beams." Advanced Materials Research 243-249 (May 2011): 514–20. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.514.

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Based on strut-and-tie model (STM) in deep beams, steel truss reinforced concrete (STRC) deep beam was developed. Experimental investigations of mechanical performances of STRC deep beams were carried out, and results show that STRC deep beam is of high ultimate bearing capacity, large rigidity and good ductility; Strut-and-tie force transference model is formed in STRC deep beams, and loads can be transferred in the shortest and direct way. Then Steel reinforced concrete (SRC) strut-and-tie model (SSTM) for determining the shear strength of STRC deep beams is proposed. The contribution of SRC diagonal strut, longitudinal reinforcements, stirrups and web reinforcements to the shear strength of STRC deep beams are determined with consideration of softened effects of concrete, and for safe consideration, superposition theory is employed for SRC struts. Computer programs are developed to calculate the shear strength of STRC deep beams and verified by experimental results.

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Yu, Tao, Quansheng Sun, Chunwei Li, and Yancheng Liu. "Experimental Research on the Flexural Performance of RC Rectangular Beams Strengthened by Reverse-Arch Method." Symmetry 13, no. 9 (September 9, 2021): 1666. http://dx.doi.org/10.3390/sym13091666.

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Carbon fiber-reinforced polymer (CFRP) reinforcement technology has been widely used in the reinforcement of reinforced concrete (RC) beams. At this stage, high prestressed CFRP board reinforcement is often used in actual reinforcement. However, most reinforced bridges are designed for a long time, and the design value of the protective layer is low, and it is impossible to achieve a large prestressed tension. Therefore, this paper proposes the reverse-arch method to paste the CFRP board and apply low prestress to strengthen the symmetrical RC beam. Through the three-point forward loading test, the cracking load, ultimate load, crack width, mid-span deflection, strain and failure mode of a reverse-arch method-pasted CFRP board-reinforced beam, a directly pasted CFRP board-reinforced beam and an unreinforced beam are compared. The results show that the load-bearing capacity and stiffness of the test beam can be improved by pasting CFRP plates with anti-arch method, but the ductility of the test beam is reduced. Compared with the unreinforced beam, the maximum cracking load and ultimate load are increased by 56% and 63% respectively. The reverse-arch method can produce low prestress, improve the stiffness and bearing capacity of members, and has a good prospect of engineering application.

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Akhras, George, and John A. Fedoruk. "A prototype knowledge-based expert system for the design and detailing of reinforced concrete beams." Canadian Journal of Civil Engineering 18, no. 6 (December 1, 1991): 1005–12. http://dx.doi.org/10.1139/l91-123.

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Most computer programs developed for reinforced concrete beam design either analyze a given cross section for load capacity or offer a limited solution from which the engineer must continue toward the final design. These programs are very useful in performing many tedious calculations. However, they generally do not offer assistance in areas of design that require intuitive reasoning, experiential knowledge, rules of thumb, and sound engineering judgement. This type of heuristic knowledge has been incorporated into a prototype knowledge-based expert system for reinforced concrete beam design and detailing called BeamEx. BeamEx interacts with the user to advise and establish suitable parameters required for the comprehensive design of rectangular simply supported and continuous beams. It incorporates heuristic rules drawn from the governing Canadian codes and textbooks to design alternative suitable beams which are presented in graphical form. It is shown that a knowledge-based system approach can be used effectively in engineering design by encapsulating domain expertise in a program to complement and check the experience of the users in design. Key words: knowledge-based expert system, reinforced concrete, beams, design, detailing.

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Aloisio, Angelo. "Aspects of Vibration-Based Methods for the Prestressing Estimate in Concrete Beams with Internal Bonded or Unbonded Tendons." Infrastructures 6, no. 6 (June 2, 2021): 83. http://dx.doi.org/10.3390/infrastructures6060083.

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The estimate of internal prestressing in concrete beams is essential for the assessment of their structural reliability. Many scholars have tackled multiple and diverse methods to estimate the measurable effects of prestressing. Among them, many experimented with dynamics-based techniques; however, these clash with the theoretical independence of the natural frequencies of the forces of internally prestressed beams. This paper examines the feasibility of a hybrid approach based on dynamic identification and the knowledge of the elastic modulus. Specifically, the author considered the effect of the axial deformation on the beam length and the weight per unit of volume. It is questioned whether the uncertainties related to the estimate of the elastic modulus and the first natural frequency yield reasonable estimates of the internal prestressing. The experimental testing of a set of full-scale concrete girders with known design prestressing supports a discussion about its practicability. The author found that the uncertainty in estimating the natural frequencies and elastic modulus significantly undermines a reliable estimate of the prestressing state.

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Savino, Pierclaudio, Francesco Tondolo, Donato Sabia, Antonino Quattrone, Fabio Biondini, Gianpaolo Rosati, Mattia Anghileri, and Bernardino Chiaia. "Large-Scale Experimental Static Testing on 50-Year-Old Prestressed Concrete Bridge Girders." Applied Sciences 13, no. 2 (January 7, 2023): 834. http://dx.doi.org/10.3390/app13020834.

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The heritage of existing road infrastructures and in particular of bridges consists of structures that are approaching or exceeding their designed service life. Detrimental causes such as aging, fatigue and deterioration processes other than variation in loading conditions introduce uncertainties that make structural assessment a challenging task. Experimental data on their performances are crucial for a proper calibration of numerical models able to predict their behavior and life-cycle structural performance. In this scenario, an experimental research program was established with the aim of investigating a set of 50-year-old prestressed concrete bridge girders that were recovered from a decommissioned bridge. The activities included initial non-destructive tests, and then full-scale load tests followed by a destructive test on the material samples. This paper reports the experimental results of the full-scale tests conducted on the first group of four I-beams assumed to be in good condition from visual inspection at the time of testing. Loading tests were performed using a specifically designed steel reaction frame and a test setup equipment, as detailed in the present work. Due to the structural response of this first group of girders, a uniform behavior was found at both service and ultimate conditions. The failure mechanism was characterized by the crushing of the cast-in-situ top slab corresponding to a limited deflection, highlighting a non-ductile behavior. The outcomes of the experimental research are expected to provide new data for the life-cycle safety assessment of existing bridges through an extended database of validated experimental tests and models.

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Kotova, K. S., and G. S. Slavcheva. "Foam Concrete and Composite Fittings Cohesion Parameters: Experimental Result and Numerical Simulation." Materials Science Forum 992 (May 2020): 836–42. http://dx.doi.org/10.4028/www.scientific.net/msf.992.836.

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The article presents the computer simulation results and real experiment of foam concrete cohesion with glass-composite, basalt-composite and metal fittings in bending elements. Numerical simulation of beams implemented with software package “Lira-SAPR 2013” using finite element method for modeling. For real experiment used bending beam test method according to ISO 10406-1:2015. As a result, the influence of the loading level and foam concrete density on the reinforcement slipping value and foam concrete cohesive strength with reinforcement in the bending elements. The foam concrete cohesive strength with glass-composite fittings meets the standard requirements, so it can be recommended for the foam concrete bending elements reinforcement. Verification of the computer simulation results with the real experiment data allowed to establish the efficiency of the used numerical model and revealed the need to use the cohesion parameters in the "foam concrete – reinforcement" system for foam concrete structures calculations in specialized programs.

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Tamayo, Jorge Luis Palomino, Armando Miguel Awruch, and Inácio Benvegnu Morsch. "Numerical modeling of reinforced concrete structures: static and dynamic analysis." Rem: Revista Escola de Minas 66, no. 4 (December 2013): 425–30. http://dx.doi.org/10.1590/s0370-44672013000400004.

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A numerical model using the Finite Element Method (FEM) for the nonlinear static and dynamic analysis of reinforced concrete (RC) beams, plates and shells is presented in this work. For this purpose, computer programs based on plasticity theory and with crack monitoring capabilities are developed. The static analysis of RC shells up to failure load is carried out using 9-node degenerated shell finite elements while 20-node brick finite elements are used for dynamic applications. The elasto-plastic constitutive law for concrete is coupled with a strain-rate sensitive model in order to take into account high loading rate effect when transient loading is intended. The implicit Newmark scheme with predictor and corrector phases is used for time integration of the nonlinear system of equations. In both cases, the steel reinforcement is considered to be smeared and represented by membrane finite elements. Various benchmark examples are solved with the present numerical model and comparisons with other published data are performed. For all examples, the path failure, collapse loads and failure mechanism is reproduced with great accuracy.

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Watanabe, Tsutomu, Keiichi Goto, Kodai Matsuoka, and Shintaro Minoura. "Verification of Longitudinal Level Irregularity Suppression Effect at the Structural Boundary by Ballasted Ladder Track." Applied Sciences 12, no. 9 (April 20, 2022): 4150. http://dx.doi.org/10.3390/app12094150.

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The ladder sleeper, which is a type of longitudinal sleeper with long beams in the longitudinal direction of the rail, was developed for the maintenance-labor saving of ballast tracks. In this study, to quantify the load distribution performance of the ladder sleepers at the structural boundary, full-scale model tests were conducted to quantify the vibration transmission reduction effect of the ladder sleepers. Following that, numerical experiments were carried out using a three-dimensional numerical analysis model and it was revealed that the ladder sleeper can reduce the pressure on the sleeper bottom plane by approximately 70% when compared to conventional prestressed concrete sleepers. Furthermore, when laying the ladder sleeper at the structural boundary, it was shown that laying across the structural boundary may be more effective in reducing the pressure on the sleeper bottom plane than laying it in front of the structural boundary. Finally, ladder sleepers were installed on the commercial line and long-term measurements of the longitudinal level irregularity verified the effect of suppressing the longitudinal level irregularity of the ballasted ladder track.

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Danatzko, Joseph M., Halil Sezen, and Qian Chen. "SUSTAINABLE DESIGN AND ENERGY CONSUMPTION ANALYSIS FOR STRUCTURAL COMPONENTS." Journal of Green Building 8, no. 1 (April 2013): 120–35. http://dx.doi.org/10.3992/jgb.8.1.120.

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The engineering community has been striving to design more sustainable buildings in an attempt to reduce both environmental impact and energy use during all phases of design, construction and operation. Design professionals currently have very limited guidance or tools to incorporate life-cycle and sustainability concepts into their designs. After reviewing the capabilities and limitations of four current life cycle analysis (LCA) computer programs, this research has selected the Athena Impact Estimator v4.0 to perform parametric studies of structural members made up of different construction materials. The energy consumption values are calculated and compared for columns, beams, concrete suspended slabs, precast double-tee sections and various other floor types. While Athena did offer some insights based on its LCA results, this research has concluded that existing LCA and sustainability analysis programs have too few options to meet the current needs of design professionals. A more accurate, sophisticated whole-building LCA tool needs to be developed to assess sustainable properties of design alternatives and to produce the most sustainable structural systems.

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Asso, Rebecca, Marco Domaneschi, Giuseppe C. Marano, Fabrizio Palmisano, and Giuseppe Palombella. "Behavior of Half-Joints: Design and Simulation of Laboratory Tests." Infrastructures 7, no. 12 (November 24, 2022): 160. http://dx.doi.org/10.3390/infrastructures7120160.

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European countries are characterized by an extensive infrastructural network, mainly built around the 1960s and 1970s. In that period prefabrication processes were starting to gain ground, and one of the most spread and studied typologies of bridges was constituted by reinforced or prestressed concrete decks. Those structures have gone through years of service, which caused the inevitable degradation of the materials and relevant deterioration of structural elements. Moreover, the design and construction processes of that period have soon become obsolete, and the knowledge relative to the influence of detailing increased significantly. One particular element that has been commonly used has been the half-joint, which is easy to prefabricate and has a strategic impact. However, in recent years this solution is showing critical aptitudes in resisting structural degradation and material decay. In addition, structural health monitoring (SHM) strategies are gaining attention since they are a very useful tool for gathering information on the current state of the structure and then for evaluating intervention plans to improve safety. Indeed, existing bridges, despite their working age, are still crucial to the development and sustainability of community life, and their decommissioning would be an act of critical impact on the communities (e.g., economy, logistics, sustainability). This contribution presents the design and the simulation of laboratory tests on half-joints of reinforced concrete beams that will be developed at the Politecnico di Torino in a subsequent step of the present research. They are designed to test and compare different monitoring techniques along with different steel reinforcement configurations. Specifically, the first part of the manuscript focuses on a review of the literature regarding the design, strengthening, and monitoring of half-joints. Subsequently, the laboratory setup to test half-joints is presented along with the numerical simulation to support the experimental design. Laboratory tests will involve the use of monitoring systems to detect the local response of the system and also to propose new solutions specifically for this type of connection using emerging technologies. Numerical collapse simulations show the effect of different reinforcement configurations and the collapse behavior.

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KASAT, ABHINAV S., and VALSSON VARGHESE. "“FINITE ELEMENT ANALYSIS OF PRESTRESSED CONCRETE BEAMS”." International Journal of Advanced Technology in Civil Engineering, October 2012, 225–29. http://dx.doi.org/10.47893/ijatce.2012.1034.

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Concrete structural components exist in buildings and bridges in different forms. Understanding the response of these components during loading is crucial to the development of an overall efficient and safe structure.Different methods have been utilized to study the response of structural components. Experimental based testing has been widely used as a means to analyse individual elements and the effects of concrete strength under loading. While this is a method that produces real life response, it is extremely time consuming, and the use of materials can be quite costly. The use of finite element analysis to study these components has also been used. Unfortunately, early attempts to accomplish this were also very time consuming and infeasible using existing software and hardware. In recent years, however, the use of finite element analysis has increased due to progressing knowledge and capabilities of computer software and hardware. It has now become the choice method to analyze concrete structural components. The use of computer software to model these elements is much faster, and extremely cost-effective. To fully understand the capabilities of finite element computer software, one must look back to experimental data and simple analysis. Data obtained from a finite element analysis package is not useful unless the necessary steps are taken to understand what is happening within the model that is created using the software. Also, executing the necessary checks along the way, is key to make sure that what is being output by the computer software is valid. By understanding the use of finite element packages, more efficient and better analyses can be made to fully understand the response of individual structural components and their contribution to a structure as a whole. This paper is a study of prestressed concrete beams using finite element analysis to understand the response of prestressed concrete beams due to transverse loading.

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Zhang, Chengquan. "Reinforcement performance of prestressed unbonded carbon fiber reinforced polymer (CFRP) in continuous beam under artificial intelligence technology." Journal of Computational Methods in Sciences and Engineering, October 28, 2022, 1–15. http://dx.doi.org/10.3233/jcm226472.

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Due to the influence of various factors such as design, construction and use, concrete structures are prone to various damages and defects, so it is necessary to strengthen and repair, and the strengthening technology of carbon fiber external bonding plate is one of the important methods. Therefore, a study on the strengthening performance of prestressed unbonded carbon fiber reinforcement of continuous beams under artificial intelligence technology is proposed. Concrete beams were tested, including the flexural properties of damaged concrete beams strengthened with carbon fiber reinforced polymer, the flexural properties of damaged concrete beams strengthened with prestressed CFRP, and the shear properties of damaged concrete beams strengthened with CFRP. On the basis of experimental research, the calculation methods of flexural capacity, stiffness, crack width and shear capacity of reinforced beams are studied theoretically. The shear strengthening tests of fiber grating and ECC composites are carried out. Through the comparison with ordinary reinforced concrete and carbon fiber reinforced concrete specimens, the crack development, ultimate deflection, ultimate bearing capacity and failure mode of different specimens are studied. The experiments show that the research method provides a new idea for the application of new materials such as carbon fiber grating in structural strengthening engineering.

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Ribeiro, Karla Demoner, Thiago Tononi Turini, Lorenzo Augusto Ruschi e. Luchi, and Adenilcia Fernanda Groberio Calenzani. "Behavior of composite beams with external prestressing in sagging moment regions." Revista IBRACON de Estruturas e Materiais 14, no. 4 (2021). http://dx.doi.org/10.1590/s1983-41952021000400005.

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Abstract Prestressed composite steel-concrete structures are scarcely used due to a lack of clear standardized design guidelines and formulations on the subject. The present research aims to present design methodologies for steel-concrete composite beams with external pretension applied via straight tendons. A computer program to perform structural analysis of such beams was developed based on two different methodologies: the first one is presented in ABNT NBR 8800:2008, in which the guidelines for the design of composite beams with compact webs are adjusted to include the effects of the pretension force. The second methodology is extracted from international literature and presents a structural design process based on stress distribution on the beam. Ninety prestressed and thirty non-prestressed beams were analyzed and designed with the aforementioned computer program to evaluate the influence of beam length, degree of symmetry of the steel profile and eccentricity of the pretension force on the mechanical resistance of the beams. It was observed that, although the prestressing force considerably improved resistance to bending, it introduced high compression stresses on the steel profile; hence, the pre-stressing of composite beams is proved efficient only for steel profiles with symmetrical cross-sections.

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"Design Aids for Prestressed Concrete Double Tee Beam with Web Opening Associated with the Variation of its Compressive Strength." International Journal of Recent Technology and Engineering 8, no. 3 (September 30, 2019): 8509–20. http://dx.doi.org/10.35940/ijrte.e1981.098319.

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Precast prestressed concrete double tee beams are one of the most popular precast concrete floor framing system, which it’s being from necessity to carry out many researche’s studies to predict a powerful tool to simulate its full behavior. Herein, an investigating studies have been carried out to check the validity of increasing span length by increasing concrete compressive strength with the existence of web opening. The main advantage of these openings is that mechanical equipment can pass through the webs of double tees instead of under them. This reduces the floor-to- floor height and the overall cost of the building. Another advantage is a slight reduction in double tee weight that would improve the demand on the supporting frame both under gravity loading and seismic excitation. All of that advantage will be more benefit with larger span length, that will be limited within the existence of web opening. A numerical model was prepared checked to simulate the nonlinear behavior of prestressed concrete beams under monotonically increasing load. Within such numerical model, tested programs were made to predict longer span in considerable concrete compressive strength, that chosen from practical available values can be achieved in the site. After all of that a design charts were prepared to be a guide tool to engineers when double tee beams with web opening required to cover more span length. Curves are classified and presented considering the most common typical sections of the double tee beams modified to show the flexibility could be obtained when changing concrete compressive strength.

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Chen, Cheng, and Hamdy Mohamed. "Optimal Solution of the Fractional Differential Equation to Solve the Bending Performance Test of Corroded Reinforced Concrete Beams under Prestressed Fatigue Load." Applied Mathematics and Nonlinear Sciences, July 15, 2022. http://dx.doi.org/10.2478/amns.2022.2.0035.

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Abstract With the help of fractional differential equations, this article studies the failure morphology, fatigue strength, and fatigue life of corroded reinforced concrete beams under fatigue loading. Studies have shown that the mid-span deflection of low-corrosion reinforced concrete beams is smaller than that of uncorroded reinforced concrete beams. The corrosion-fatigue coupling effect accelerates the fatigue crack growth rate of steel bars. This reduces the fatigue modulus of concrete and causes the stiffness of the beam to degrade. The research results provide a theoretical basis for the fatigue performance evaluation of corroded reinforced concrete beams.

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Journal articles on the topic 'Prestressed concrete beams Computer programs'

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