不同理论在分析箱形梁畸变效应时的差异  

Differences Between Two Different Theories in Analyzing Distortion Effect of Box Girder

作　　者：王晨光[1] 张元海[1] WANG Chen-guang;ZHANG Yuan-hai(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070

出　　处：《兰州交通大学学报》2021年第4期20-25,共6页Journal of Lanzhou Jiaotong University

基　　金：国家自然科学基金(51968040);兰州交通大学青年基金(2019024)。

摘　　要：为了更准确地分析箱形梁在偏心荷载作用下的畸变效应,对比了板元分析法、能量分析法两种不同理论在分析箱形梁框架畸变变形、畸变翘曲变形时的内在联系与差异,推导出了计算箱形梁畸变内力的控制微分方程.采用数值算例对两种不同理论及ANSYS有限元法的计算结果进行分析.结果表明:两种不同畸变理论计算得到的畸变几何特性参数λP、λE相等,且对于直腹板箱梁,两种理论具有统一性.畸变翘曲正应力随顶、底板长度之比b_(t)/b_(d)的增大而逐渐减小,采用有限元法计算时降低幅度最大,采用板元分析法计算时降低幅度最小.当b_(t)/b_(d)<1.4时,采用板元分析法计算所得的畸变翘曲正应力与ANSYS有限元法计算所得结果更为接近;而当b_(t)/b_(d)>1.8时,采用能量分析法计算所得的畸变翘曲正应力更为准确.In order to analyze the distortion effect of box girder under eccentric load more accurately,the internal relations and differences between the plate element analysis theory and the energy analysis theory in analyzing distortion deformation and distortion warping deformation of the box girder were compared,and the control differential equations for calculating the distortion internal force were derived respectively by the two theories.A numerical example was used to analyze the results calculated by the two different theories and the ANSYS finite element method.The results show that the geometric characteristic parameters,λP andλE,calculated by the two different distortion theories are equal,and the two theories are uniform for straight web box girder.With the increase of the length ratio of top plate to bottom plate,b_(t)/b_(d),the distortion warping normal stresses decrease gradually.The decreasing amplitude is largest when using ANSYS finite element method and smallest when using the plate element analysis theory.When b_(t)/b_(d)<1.4,the distortion warping normal stresses calculated by the plate element analysis theory are closer to those by ANSYS finite element method.When b_(t)/b_(d)>1.8,the distortion warping normal stresses calculated by the energy analysis method are more accurate.

关 键 词：箱形梁 畸变效应 板元分析法 能量分析法 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]