波形钢腹板箱梁畸变应力分析

在对梯形截面箱梁的畸变角给出一般定义的基础上，根据传统混凝土箱形梁的理论及波形钢腹板的力学特性，对波形钢腹板组合箱梁的畸变翘曲应力进行推导，应用基于势能驻值原理的能量变分法，建立了以所定义的畸变角为未知量的控制微分方程，并给出其初参数解.采用初参数法求出波形钢腹板组合箱梁的畸变角和畸变双力矩，最终得到纵向畸变翘曲应力.通过算例对比分析了传统混凝土箱梁和波形钢腹板组合箱梁顶板与腹板及底板与腹板交点处的畸变翘曲应力，分析结果表明:由于波形钢腹板组合箱梁腹板的纵向刚度很小几乎为零，所以在波形钢腹板组合箱梁底板与腹板交点处产生的翘曲应力大于混凝土箱梁底板与腹板交点处的对应值.

Stress Analysis on Distortion of Corrugated Steel Web Box Girders

Based on the definition of the distortion angle presented for trapezoidal-section box girders, according to the theories for the traditional concrete box girder and the mechanical properties of the corrugated steel web, the distortion warping stresses of the corrugated steel web composite box girder were deduced. The governing differential equations for the distortion angle were established with the energy variation calculus method based on the principle of stationary potential energy, and the initial parameter solutions to the equations were achieved. With the initial parameter method the distortion angle and the distortion double moment of the corrugated steel web composite box girder were obtained. Finally, the longitudinal distortion warping stresses were got. Contrastive analysis of the distortion warping stresses were done between the traditional concrete box girder and the corrugated steel web composite box girder. The analysis results show that, due to the negligible longitudinal stiffness of the corrugated steel web, the warping stress at the web-bottom intersection of the corrugated steel web composite box girder is much larger than that of the concrete box girder.