Behavior of Reinforced Concrete Elements Subjected to Tri-Directional Shear Stresses

Author(s):  
Moheb Labib ◽  
Yashar Moslehy ◽  
Ashraf Ayoub
Teknik ◽  
2021 ◽  
Vol 42 (2) ◽  
pp. 106-116
Author(s):  
Nuroji Nuroji ◽  
Muhammad Rony Asshidiqie ◽  
Sukamta Sukamta ◽  
Ay Lie Han

The weakness of full-scale testing of reinforced concrete elements in a laboratory is the long period, both to prepare and test specimens and the high-cost, resulting in a limited number of specimens. The heavy specimen creates another difficulty during set-up. Data accuracy depends on apparatus precision, laboratory conditions, and the technicians' expertise in experimenting. A finite element model was constructed to simulate a reinforced concrete element subject to high flexure and shear stresses induced by vertical and horizontal forces to overcome these constraints. The model can further be utilized to evaluate the effects of independent variables on the behavior of the member. The model was validated both numerically and experimentally to ensure accuracy and precision. The numerical validation was conducted through a sensitivity analyses process on the finesses of meshing and loading incrementation. At the same time, the load-deformation data and the crack propagation of identical laboratory-tested elements were utilized for validation of the experimental data. It was proven that the developed model predicts the behavior of the beam to a high degree of correctness. The model can further be used as a tool for analyses in the field.


2018 ◽  
Vol 15 (3) ◽  
pp. 434-444
Author(s):  
Y. V. Krasnoshchekov

Introduction. The article presents results of the empirical dependence analysis of transverse force in the inclined section of reinforced concrete elements.Materials and methods. Long-term application of such dependence at the reinforced concrete design demonstrates high parameters’ reliability. Thus, analyzed information could be used in innovated calculation model, which includes joint action of cross forces and bending moments.Results. The analysis of empirical dependence by the design standards seems to obtain information about the limit value of shear stresses in the compressed zone of inclined concrete and their interrelations with normal stresses. The results of the analysis were tested on computer models of the beam using finite elements. It does, however, assume that the shear resistance is specifically related to compression resistance by means of a special coefficient, which could be determined by computer simulation.Discussion and conclusions. The calculated values of the inclined section of reinforced concrete elements in the transverse bending could be specified by experimental or computer modeling.


Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
М. П. Нажуев

Состояние проблемы. Железобетонные элементы изготавливаются, как правило, по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что реализуется лишь в вибрированных колоннах. Результаты. В рамках диаграммного подхода предложены итерационный, приближенный и упрощенный способы расчета несущей способности железобетонных вибрированных, центрифугированных и виброцентрифугированных колонн. Выводы. Расчет по диаграммному подходу показал существенно более подходящую сходимость с опытными данными, чем расчет по методике норм, а также дал лучшие результаты при использовании дифференциальных характеристик бетона, чем при использовании интегральных и, тем более, нормативных характеристик бетона. Statement of the problem. Reinforced concrete elements are typically manufactured according to three basic technologies - vibration, centrifugation and vibrocentrifugation. However, all the basic calculated dependencies for determining their bearing capacity were derived using the main postulate, i.e., the constancy and equality of the characteristics of concrete over the cross section, which is implemented only in vibrated columns. Results. Within the framework of the diagrammatic approach, iterative, approximate and simplified methods of calculating the bearing capacity of reinforced concrete vibrated, centrifuged and vibrocentrifuged columns are proposed. Conclusions. The calculation according to the diagrammatic approach showed a significantly better convergence with the experimental data than that using the method of norms, and also performs better when using differential characteristics of concrete than when employing integral and particularly standard characteristics of concrete.


2021 ◽  
Vol 2 (1) ◽  
pp. 174-194
Author(s):  
Luís Bernardo ◽  
Saffana Sadieh

In previous studies, a smeared truss model based on a refinement of the rotating-angle softened truss model (RA-STM) was proposed to predict the full response of structural concrete panel elements under in-plane monotonic loading. This model, called the “efficient RA-STM procedure”, was validated against the experimental results of reinforced and prestressed concrete panels, steel fiber concrete panels, and reinforced concrete panels externally strengthened with fiber-reinforced polymers. The model incorporates equilibrium and compatibility equations, as well as appropriate smeared constitutive laws of the materials. Besides, it incorporates an efficient algorithm for the calculation procedure to compute the solution points without using the classical trial-and-error technique, providing high numerical efficiency and stability. In this study, the efficient RA-STM procedure is adapted and checked against some experimental data related to reinforced concrete (RC) panels tested under in-plane cyclic shear until failure and found in the literature. Being a monotonic model, the predictions from the model are compared with the experimental envelopes of the hysteretic shear stress–shear strain loops. It is shown that the predictions for the shape (at least until the peak load is reached) and for key shear stresses (namely, cracking, yielding, and maximum shear stresses) of the envelope shear stress–shear strain curves are in reasonably good agreement with the experimental ones. From the obtained results, the efficient RA-STM procedure can be considered as a reliable model to predict some important features of the response of RC panels under cyclic shear, at least for a precheck analysis or predesign.


2021 ◽  
Vol 11 (5) ◽  
pp. 2292
Author(s):  
Alaaeldin Abouelleil ◽  
Hayder A. Rasheed

Nonlinear analysis of structural members is vital to understand the behavior and the response of reinforced concrete members. Even though most design procedures concentrate on the ultimate stage of response towards the end of the post-yielding zone as the decisive design criterion, the structural members usually function at the service load levels within the post-cracking zone. Therefore, cracking is a critical aspect of concrete behavior that affects the overall response of reinforced concrete beams. The initiation and the propagation of the cracks are affected directly by the tension and shear stresses in the beam. In flexural beams, the tensile stresses dominate the crack onset and its growth. Cracks in reinforced concrete flexural beams leave non-cracked regions in between the cracked sections. In order to apply a consistent analysis strategy, the smeared crack approach averages the behavior of these different cracked sections and uncracked in between regions to generate an accurate global response of the entire beam. This study presents a numerical constitutive tensile model that captures the complete tensile response of the reinforced concrete flexural member, in terms of averaged/smeared crack response. As a second step, this model was examined against a large pool of experimental data to validate its accuracy. Overall, the main objective of this study is to develop a representative constitutive tensile model for reinforced concrete flexural members and validate its accuracy against experimental results. The full nonlinear sectional response is analytically realized, based on the assumed trilinear moment–curvature response and the assumed trilinear moment–extreme fiber compressive strain response. This is considered as the secondary outcome of the present study.


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