波形钢腹板箱梁考虑腹板局部纵向刚度影响的扭转效应分析

Analysis on the torsion effect of box girders with corrugated steel webs considering local longitudinal stiffness of webs

为了更加合理地分析波形钢腹板组合箱梁的约束扭转效应,考虑了顶底板对波形钢腹板的约束作用,引入波形钢腹板共同抗弯区的概念,同时考虑波形钢腹板的手风琴效应,提出一种分析约束扭转效应的解析法.通过引入新的广义扇性坐标分布模式,在乌曼斯基第二理论的基础上推导了约束扭转翘曲应力的计算公式.结合数值算例对比分析了所提方法与传统方法计算结果及ANSYS有限元结果的差别,确定出合理的共同抗弯区高度,验证了所推导公式的正确性.研究结果表明:在考虑了顶底板对波形钢腹板约束作用后的计算结果与传统方法相比更加接近有限元分析结果,且与有限元结果总体上吻合良好;共同抗弯区内的扭转翘曲正应力可达到弯曲正应力水平,这说明在波形钢腹板箱梁约束扭转分析中考虑顶底板对腹板的约束作用是合理的.

In order to analyze the restrained torsion effect of composited box girders with corrugated steel webs more reasonably,the restraining effect of top and bottom plates on the corrugated steel webs is considered.The concept of the common bending section of corrugated steel webs is introduced.Considering the accordion effect,an analytical method for analyzing the torsion effect is proposed.Introducing a new generalized sectorial coordinate distribution model,the calculation formula of restrained torsion warpage stress is deduced based on the second theory of Umanskii.Through a numerical example,the differences among the results of the proposed method,the traditional method and ANSYS finite element method are analyzed.The reasonable height of the common bending section is determined,and the correctness of the derived formula is verified.The results show that the calculation results after considering the restraining effect of the top and bottom plates on the corrugated steel webs are closer to the finite element analysis results compared with the traditional method,and the results are in good agreement with the finite element results.The normal stress in the common bending section can reach the bending normal stress level,showing that it is necessary to consider the restraint effect of top and bottom plates on corrugated steel webs in the analysis of restrained torsion of box girders with corrugated steel webs.