Torsional performance of web-embedded U-shaped steel-concrete composite beams

Web-embedded U-shaped steel-concrete composite beam (WUSCB) was designed and eight specimens were tested to study the torsional properties and failure modes considering the parameters of concrete flange width , slab thickness , concrete web height, and U-shaped steel thickness. Initial torsional stiffness and torsional capacity of WUSCBs were evaluated based on the experimental results of torque-torsion ratio curve and stress distribution. A finite element model was established to investigate the effects of U-shaped steel thickness, concrete flange width, and slab thickness. According to the study results, a torsional design method for WUSCBs is proposed, which enables the determination of initial torsional stiffness, cracking torque, and torsional capacity. • A test research ofeight WUSCB (Web-embedded U-shaped steel-concrete composite beam) specimens was carried out under pure torsion. • A finite element model for WUSCB was developed and parametric analysis was conducted. • Calculation methods for initial torsional stiffness, cracking torque, and torsional capacity were proposed.