Nonlinear Finite Element Analysis of Reinforced Concrete Beams Subjected to Torsion

Abstract

This work aims to investigate the behavior of rectangular-section of reinforced concrete beams subjected to torsion by using the finite element method. An analytical study is presented in the current work on thirty-four beam specimens divided into two series. Compressive strength of concrete is the main parameter for first series which contains sixteen specimens (high strength concrete HSC and normal strength concrete NSC), the spacing of the stirrups is also investigated in this series. Second series, includes eighteen beams investigated for the effect of some parameter on the torsional capacity. These parameters are amount of longitudinal and transverse reinforcement, yield strength of longitudinal and transverse steel, reinforcement stresses, and crack patterns of HSC and NSC beams.The results showed that for RC beams, the transverse reinforcement is more effective in resisting the applied torque, it is preferable to use a higher ratio of transverse reinforcement for the NSC and HSC beams, where the increase in ultimate torque was about 94% for an increase in the ratio from 6% to 16%, the effect of yield strength of steel is about 4.1% by changing the yield strength by 13.6% from 440 MPa to 500 MPa. The increasing of transverse reinforcement spacing significantly improves and increases the ultimate twisting angle. The mode of failure for the RC beams is more affected by the reinforcement ratio and the typical mode of failure for rectangular section beams is diagonal tension failure for both concrete grades.