随机人行激励模型改进及应用  

Improvement of stochastic walking excitation model and its application

作　　者：丁阳[1] 米仓[1] 

机构地区：[1]天津大学建筑工程学院滨海土木工程结构与安全教育部重点实验室,天津300072

出　　处：《振动与冲击》2012年第20期56-60,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金面上项目(50978181);高等学校博士学科点专项科研基金项目(20090032110043)

摘　　要：为准确描述行人间人行激励的差异性和单人激励各相似周期的差异性,基于Zivanovic模型提取样板周期曲线,通过非线性最小二乘拟合,并考虑单人激励各周期、幅值和冲量的随机特性,提出一种改进的随机人行激励模型;与已有常用人行激励模型比较表明,改进模型能更有效地模拟人行激励的时频域特性,与实测时程更加吻合。以天津西站站房结构为例,将人体等效为双自由度质量弹簧阻尼系统,建立人-结构耦合动力平衡方程,采用逐步积分法进行随机人行激励下的结构振动响应分析;结果表明:采用改进随机人行激励模型分析的结构振动响应频域分布更宽,且激励中高频成分对结构振动有一定贡献;考虑人-结构耦合作用,将减小结构振动响应,但影响较小。An improved stochastic walking excitation model considering random variations of periods,amplitudes and impulses was proposed to accurately describe the individual difference of walking excitation among pedestrians and the similar period difference of a single walking time series.In the model,the template cycle was extracted based on Zivanovic model and optimized using the non-linear least-square curve fit method.The improved model was verified to be superior to other existing models in terms of simulating both time and frequency domain characteristics of walking excitation,and agreed better with the real measured time histories.The influence of human body on structural vibration responses was further considered after a human body was taken as a mass-spring-damper model with two degrees of freedom,the human-structure coupled dynamic equations were established based on the improved model,and the pedestrian-induced structural vibration responses were solved with the direct integration method.A numerical example of Tianjin West Railway Station structure was studied.The results indicated that by employing the improved model,the frequency distribution of the structural responses is wilder and the higher excitation frequency components obtained with the model has non-negligible effect on the structural responses,in addition,the coupled effect between human and structure reduces the structural responses but a little.

关 键 词：随机人行激励 人致振动 样板周期 耦合作用 频谱分析 

分 类 号：O327[理学—一般力学与力学基础]