Three-Dimensional Fiber-Based Models of Precast and Cast-in-Place Reinforced Concrete Columns

2022 ◽  
Vol 148 (3) ◽  
Author(s):  
Haider M. Al-Jelawy ◽  
Kevin R. Mackie
Author(s):  
Matheus Wanglon Ferreira ◽  
Luiz Carlos Pinto da Silva Filho ◽  
Mauro de Vasconcellos Real

ABSTRACT: A three-dimensional (3D) transient numerical model for thermomechanical analysis developed with Finite Element Method (FEM) using the software ANSYS 19.1 is exposed in this paper. The proposed model aims to predict the structural behavior of reinforced concrete columns in a fire situation since it is known that high temperatures significantly reduce their mechanical resistance. For this, the main factors that govern their structural behavior should be considered. Analyses obtained by the proposed model were validated with results from experimental data, evidencing a good correlation between numerical and experimental fields.


2018 ◽  
Vol 26 (3) ◽  
pp. 75-97
Author(s):  
Mazen Dewan Abdulla ◽  
Zahraa Abbas Khaduier

This paper presents the results of a study to have better understanding of structural behavior of the reinforced concrete (RC) column wrapped by carbon fiber reinforced polymer (CFRP) sheets. In this study, 3D F.E model has been presented using ANSYS computer program (Release 16.0) to analyze reinforced concrete columns strengthened with CFRP composites , to evaluate the gain in performance (strength and ductility) due to strengthening, and to study the effect of the most important parameters such as: compressive strength of concrete, modulus of elasticity of CFRP and corner radius of square columns. Three dimensional eight-node brick element (SOLID65) was used to represent the concrete, three dimensional spar element (LINK180) represented the steel and using a three dimensional shell element (SHELL41) to represent the CFRP composites. The present study has a comparison between the analytical results from the ANSYS finite element analysis with experimental data. The results of the study show that, external bonded CFRP sheets are very effective in enhancing the axial strength and ductility of the concrete columns. Inspection of


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.


2018 ◽  
Vol 12 (1) ◽  
pp. 47-61
Author(s):  
Wenjuan Lv ◽  
Baodong Liu ◽  
Ming Li ◽  
Lin Li ◽  
Pengyuan Zhang

Background: For reinforced concrete structures under different humid conditions, the mechanical properties of concrete are significantly affected by the moisture content, which may result in a great change of the functional performance and bearing capacity. Objective: This paper presents an experiment to investigate the influence of the moisture content on the dynamic characteristics and hysteretic behavior of reinforced concrete column. Results: The results show that the natural frequency of reinforced concrete columns increases quickly at an early stage of immersion, but there is little change when the columns are close to saturation; the difference between the natural frequencies before and after cyclic test grows as the moisture content rises. The damping ratio slightly decreases first and then increases with the increase of moisture content; the damping ratio after the cyclic test is larger than before the test due to the development of the micro-cracks. Conclusion: The trend of energy dissipation is on the rise with increasing moisture content, although at an early stage, it decreases slightly. According to the experimental result, a formula for the moisture content on the average energy dissipation of reinforced concrete columns is proposed.


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