移动随机荷载作用下梁桥非平稳随机振动的PEM-FFT方法  

PEM-FFT for non-stationary random vibration analysis of simple -supported beam bridge under moving random load

作　　者：赵岩[1,2] 周瑞鹏 贾甜 ZHAO Yan;ZHOU Rui-peng;JIA Tian(State Key Laboratory of Bridge Engineering Structural Dynamics,Chongqing Communications Research& Design Institute,Chongqing 400067,China;Department of Mechanical Engineering,State Key Laboratory of Structural Analysis for Industrial Equipment,Dalian University of Technology,Dalian 116023,China)

机构地区：[1]重庆交通科研设计院桥梁工程结构动力学国家重点实验室,重庆400067 [2]大连理工大学工业装备结构分析国家重点实验室工程力学系,大连116023

出　　处：《计算力学学报》2019年第1期65-70,共6页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(11772084);中央高校基本科研业务费(DUT17ZD311);973计划(2015CB057804)资助项目

摘　　要：针对移动随机载荷作用下桥梁结构非平稳随机振动问题,建立了一种基于频域分析的虚拟激励-傅里叶变换方法(PEM-FFT)。与通常的非平稳随机振动的时频分析方法不同,提出的方法完全在频域上执行。其主要特色是能够给出随机输入与随机输出的频域关系,表明移动载荷作用下结构非平稳随机振动分析仅需对载荷的确定性移动函数项进行计算。数值算例考虑了等截面/变截面简支梁受移动随机载荷作用的问题,首先与通常的时频分析方法进行对比,验证了PEM-FFT方法的正确性和有效性,进一步讨论了不同结构形式以及不同载荷移动速度对响应演变统计量的影响。A frequency domain analysis method for non-stationary random vibration of bridge structures under moving random loads is presented.Unlike the time-frequency analysis methods for non-stationary random vibration,the proposed method is fully implemented in frequency domain.One of the main features of this method is capable of getting the relationship between random input and random output in frequency domain,which shows that the analysis of non-stationary random vibration caused by a moving load only needs to compute the moving function item as the determined part of input loads.The numerical example is about a simple-supported beam of a constant or variable cross section under moving random load.First of all,the time-frequency analysis method is used to validate the proposed method,and then the effect of the moving loads at different speeds and structures on the response of the statistical variables is analysed.

关 键 词：移动随机载荷 非平稳 随机振动 频域分析 虚拟激励-傅里叶变换方法 

分 类 号：O324[理学—一般力学与力学基础]