Numerical Investigation on Torsional Reinforced Concrete Stepped Beams with Various Reinforcement Patterns

A Finite Element Model (FEM) for Reinforcement Concrete Stepped Beams (RCSBs) is presented in this numerical investigation, aiming to capture the effect of Stirrups Spacings (SSs), Stirrups’ Diameters (SDs), Longitudinal Reinforcement Ratio (LRR), and Longitudinal Reinforcement Patterns (LRP) as a various parameters effect on the structural performance of RCSBs under pure torsion loads. Implemented using ABAQUS and validated against previous experimental results, the study included a parametric analysis of 10 beams divided into 4 groups, focusing on the distance of SSs with varied lengths, SDs with varied diameter and configurations, more ratios of LRR, and different LRP of longitudinal bars. To compare the beams, both elastic stiffness (K) and ductility (D) and absorbed energy (E) were calculated. Straight beams exhibit superior torsional properties than the (RCSBs). The results indicated that changing in (LRR), (SDs), (LRP), (SSs) led to a decrease in the torsional moment capacity by 3-5%, 9-13%, 26-32%, 17-36%, respectively of their values to beam B0. In addition to enhancing the elastic and ductile stiffness as well as the absorbed energy of each specimen.