差分法计算钢箱-混凝土组合梁的纯扭转刚度及剪应力

Difference Method for the Calculation of Torsion Stiffness and Shearing Stress of Steel Box-concrete Composite Beam

通过分析纯扭转应力函数的特点,采用差分法建立钢箱-混凝土组合截面不同材料区域内部各节点的差分方程.并根据组合截面的特征,将应力函数在材料交界面附近做线性化处理,建立基于不同材料的一阶导数关系式,得到补充方程.联立差分方程和补充方程即可求解此类复杂截面的扭转问题,得到扭转剪应力及截面扭转常数.算例表明,钢箱-混凝土组合梁的扭转特性明显优于型钢-混凝土板组合梁.

Based on the analysis of the character of the pure torsion stress function,difference method is used to set up difference equations about every node on different material sectional area.Then the compensatory equations are got by linearizing the pure torsion function near the interface between different materials,according to the feature of this kind of section.With these difference equations and compensatory ones,the torsion problem of this kind of beam can be solved to get its torsional shear stress and constant of torque.Numerical examples present that the torsional capacity of box steel-concrete beams is far beyond that of shape steel-concrete ones.