Numerical Study of RC Beams with Web Opening under Pure Torsion

In contemporary construction, particularly in high-rise buildings, incorporating web openings in reinforced concrete (RC) beams has become a practical necessity to accommodate mechanical and electrical services. These openings help reduce the required story height, leading to more efficient space usage. However, their presence can influence the beam’s structural behavior, especially its ability to resist torsional loads—an area that has not been thoroughly investigated. At present, there is a lack of clear design recommendations for RC beams with web openings subjected purely to torsion. This study explores the torsional behavior of such beams through finite element analysis (FEA), using ANSYS 15 software. A total of 324 beam models were simulated: varying in opening dimensions, concrete compressive strength, and both longitudinal and transverse reinforcement ratios. The output results showed that increasing the size of the opening led to a noticeable decrease in torsional capacity, while stronger concrete and higher reinforcement ratios improved it. To support the numerical findings, a statistical model was developed using Statistical Package for the Social Sciences (SPSS) to estimate the torsional strength based on the studied parameters. The resulting equation demonstrated strong predictive accuracy, with a coefficient of determination (R²) of 0.94. These results contribute to a deeper understanding of RC beam behavior under torsion and offer a useful tool for future design considerations.