钢-混凝土组合梁收缩徐变分析的有限元方法

基于按龄期调整的有效模量法,提出了部分剪力连接钢-混凝土组合梁在长期荷载作用下收缩徐变分析的简化有限元模型,并通过建立特殊的剪力连接件单元刚度矩阵和利用Newton-Raphson迭代方法考虑滑移效应,同时考虑了负弯矩区混凝土板开裂对组合梁刚度和强度的影响。利用该模型计算了连续组合梁在长期荷载作用下的挠度、应力、滑移量,计算结果与已有的理论计算结果和实验结果吻合,证明本模型用于分析钢-混凝土组合梁收缩徐变是可靠的。

FINITE ELEMENT ANALYSIS OF CREEP AND SHRINKAGE OF STEEL-CONCRETE COMPOSITE BEAMS

Based on the age-adjusted effective modulus method, this paper presents a simplified finite element model for analysis of creep and shrinkage of steel-concrete composite beams with incomplete interaction. The shear connector element stiffness matrix considering slip is derived. Newton-Raphson solution procedure is used to calculate the effect of slip between concrete slab and steel beam. This model also accounts for the effect of concrete slab cracking on rigidity and strength of composite beam. With this finite element model, deflection, stress and slip of a continuous composite beam under long-term load are computed. Numerical results are compared with the test results and available values of other numerical methods, and good agreement is reached. It is shown that the model is reliable in the analysis of steel-concrete composite beams.