基于改进广义坐标法的箱梁反对称变形效应分析  

Analysis on anti-symmetric deformation effect of box girders based on the improved generalized coordinate method

作　　者：刘泽翔 张元海[1] Liu Zexiang;Zhang Yuanhai(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：《东南大学学报（自然科学版）》2024年第5期1193-1200,共8页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(52368020,51968040);兰州交通大学基础研究拔尖人才计划资助项目(2022JC17);甘肃省优秀研究生“创新之星”资助项目(2022CXZX-527).

摘　　要：为分析箱梁的反对称变形效应,考虑扭转与畸变的耦合影响,给出一种分析箱梁反对称变形效应的解析法.考虑悬臂板的影响,基于广义坐标法的变形假定合理假设位移模式,根据势能驻值原理推导变形控制微分方程并给出变形状态向量的初参数解.采用简支箱梁算例验证了理论方法的合理性.结果表明:畸变内力矩在荷载作用截面发生突变,梁高变化对畸变内力矩的支座处量值有显著影响;跨中截面底板角点的畸变、扭转翘曲正应力量值比为5.51,畸变翘曲正应力占主导地位,但扭转翘曲正应力也不可忽视;按耦合变形计算的跨中截面扭转角相比扭转理论结果减小了13.37%;与独立计算扭转和畸变,再将应力结果相加的方法相比,按耦合变形计算的顶板翘曲正应力偏安全,2种方法计算的底板翘曲正应力接近.To analyze the anti-symmetric deformation effect of box girders,considering the coupling effect of torsion and distortion,an analytical method was proposed to analyze the anti-symmetric deformation effect of box girders.Considering the influence of cantilever plates,the displacement mode was reasonably assumed based on the deformation assumption of the generalized coordinate method.According to the principle of stationary potential energy,the governed differential equations for deformation were derived.The initial parameter solution of the deformation state vector was then given.The rationality of the theoretical method was verified using a simply supported box girder example.The results show that the distortion internal moment suddenly changes at the load acting section.The variation of beam height has a significant impact on the value of distortion internal moment at the support.At the mid-span section,the ratio of distortion and torsion warping normal stress at the corner of the bottom plate reaches 5.51.The warping normal stress due to distortion dominates,but the warping normal stress due to torsion cannot yet be ignored.The torsion angle of the mid-span section calculated on the basis of coupled deformation reduces by 13.37%compared with the torsion theory results.Compared with the method of independently calculating torsion and distortion and then adding up the stress results,the warping normal stress of the top plate calculated on the basis of coupled deformation is relatively safe.The warping normal stress values of the bottom plate calculated by these two methods are close.

关 键 词：薄壁箱梁 耦合变形 反对称变形效应 广义坐标法 初参数解 

分 类 号：U448.213[建筑科学—桥梁与隧道工程]