摘要
研究了作用在梁上的均匀分布人群对梁的动力特性的影响。将人群简化为均匀分布的弹性质量模型,考察了无阻尼的弹性质量和有阻尼的弹性质量两种模型对简支欧拉梁的动力特性的影响,得到了人群和梁耦合系统的频率和阻尼的解析表达式。并以此研究了分布质量与梁的质量之比对梁的频率和阻尼比的影响,得到了人群对结构动力特性影响的定性规律。结果表明:耦合系统在人体振动基频处分支出一系列的振动频率,并且当分布人群质量与结构质量之比达到一定程度时,均布的人群会对梁的振动特性产生显著的影响,明显改变梁的自振频率,显著提高梁振动的阻尼比。最后研究了梁的振动频率对人群-梁耦合系统阻尼比的影响。
This paper studies effects of modal properties of a simply supported Euler beam occupied by a uniformly distributed crowd. The crowd is modeled as uniformly distributed mass- spring-damper system or mass- spring system. Both these two models are studied to investigate the influence of the occupied crowd on the modal properties of the beam. Analytical solutions of the natural frequencies and damping ratio of the crowd-beam system are obtained. The mass ratio of the crowd to the beam is taken as a key parameter, whose effect on the natural frequencies and the damping ratios of the crowd-beam interaction system is studied, and qualitative conclusions are reached on how the crowd affects the properties of the beam. Results demonstrate the branching a bound of natural frequencies of the crowd-beam interaction system from the natural frequency of the human body; when the mass ratio of the crowd to the beam is large enough, the dynamic characters of the beam are changed greatly, and the damping ratio of the coupling system is increased significantly as well. At the end of this paper, the effect of the natural frequency of the beam on the damping ratio of the coupling system is investigated.
出处
《工程力学》
EI
CSCD
北大核心
2012年第8期189-194,共6页
Engineering Mechanics
基金
教育部博士点基金项目(200804970007)
湖北省自然科学基金重点项目(2010lj0015)
国家自然科学基金面上项目(51178365)
关键词
动力特性
人.结构相互作用
人体动力学模型
人群荷载
解析解
dynamic properties
crowd-structure interaction
dynamic model of human body
crowd-load
analytical solution
