横向冲击作用下高桥墩的几何非线性动力稳定性

发布时间：2018-03-27 22:07

本文选题：高桥墩　切入点：横向冲击荷载　出处：《应用力学学报》2014年06期

【摘要】：考虑大变形的影响,建立了高桥墩在横向冲击荷载作用下的非线性动力学基本方程式;通过位移形函数假设,采用伽辽金积分方法得到了时间变率的动力学控制方程;对时间变率的非线性微分方程进行数值求解,给出了不同冲击荷载作用下不同柔度高桥墩的位移响应曲线以及其从产生横向振动到失稳的全过程,得到了横向冲击时高桥墩失稳的临界冲击荷载和失稳时刻;通过数值算例比较了三角形和矩形冲击荷载作用下高桥墩的荷载-位移响应曲线;分析了横向冲击力幅值、冲击区域大小、冲击持续时间、高桥墩柔度、桥面质量大小对位移幅值响应曲线、临界冲击荷载、失稳时刻的影响。结果表明:无论是在矩形还是三角形形式横向冲击作用下,随着冲击区域的增大高桥墩的振动幅值变大;桥面简化质量越大,高桥墩失稳的临界冲击载荷越小;柔度越大时,高桥墩失稳的临界冲击荷载幅值越小;对于矩形冲击,当冲击持续时间大于1s后,冲击持续时间的增加对高桥墩的稳定性无明显影响;对于三角形冲击荷载,随着冲击持续时间的增大高桥墩的振动幅值变大。
[Abstract]:Considering the influence of large deformation, the nonlinear dynamic equations of high bridge piers under transverse impact load are established, and the dynamic governing equations of time varying rate are obtained by using the assumption of displacement form function and Galerkin integral method. The nonlinear differential equation with time varying rate is solved numerically. The displacement response curve of pier with different flexibility under different impact loads and the whole process from transverse vibration to instability are given. The critical impact load and instability time of high bridge pier under transverse impact are obtained, the load-displacement response curves of high bridge pier under triangular and rectangular impact loads are compared by numerical examples, and the amplitude of transverse impact force is analyzed. The effects of impact region size, impact duration, high pier flexibility, bridge deck mass on displacement amplitude response curve, critical impact load and instability time are obtained. With the increase of impact area, the vibration amplitude of high pier becomes larger; the larger the simplified mass of bridge deck, the smaller the critical impact load of high pier instability; the smaller the critical impact load amplitude of high pier instability is when the flexibility is greater; for rectangular impact, When the impact duration is more than 1 s, the increase of impact duration has no obvious effect on the stability of high bridge pier, and for triangular impact load, the vibration amplitude of high bridge pier increases with the increase of impact duration.
【作者单位】：湖南省交通科学研究院;湖南大学机械与运载工程学院工程力学系;湖南涉外经济学院计算机科学与技术学院;
【基金】：湖南省交通科技进步与创新项目(200927)
【分类号】：U441.3;U443.22

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