外包钢-砼组合梁纯扭作用下抗扭刚度的实验及数值模拟

为了研究新型外包钢-砼T形截面组合梁在纯扭作用下的变形性能，设计了5根不同配箍率的的足尺悬臂组合梁。通过对5根悬臂梁的抗扭性能的实验研究，得到了组合梁的扭矩-扭率关系曲线。利用有限元分析软件ANSYS，对组合梁的抗扭性能进行了非线性有限元分析，得到了混凝土与外包钢在极限阶段的应力云图。根据实验以及有限元结果分析了组合梁在整个加载过程中扭转刚度的变化。基于现行砼结构设计规范，提出了组合梁从开裂到极限阶段抗扭刚度的计算公式，可供组合梁受扭设计参考。把有限元模型和公式的计算结果与实验结果进行比较，三者吻合较好。

Experimental Study and FE Simulation of Deformation of Steel-encased Concrete T-Composite Beams Subjected to Torsion

In order to study the deformation behavior of steel-encased concrete T-composite beam under pure torsion action, five full size cantilever specimens with different stirrup ratio were designed. According to experimental study on the torsion performance of cantilever composite beams, a set of curves related torque with torsion angle per unit length was derived. Nonlinear finite element analysis about torsion performance of composite beams was conducted based on finite element analysis software-ANSYS, and the stress nephogram of steel-encased concrete beam in the limit stage was gained. The torsion stiffness change of composite beam during entire loading process was analyzed based on experimental and FE results. Based on current concrete design criterion, a torsion stiffness formula for composite beams from the cracking stage to the limit stage was proposed for design reference. The results obtained from FE model and above-mentioned formula are proved to be in good agreement with the experimental data.