Parametric study of modal properties of damped two-degree-of-freedom crowd–structure dynamic systems
Parametric study of modal properties of damped two-degree-of-freedom crowd–structure dynamic systems
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DOI：
10.1016/j.jsv.2003.08.052
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发表时间：
2004-07
影响因子：
4.7
通讯作者：
R. Sachse;A. Pavic;P. Reynolds
中科院分区：
文献类型：
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作者：
R. Sachse;A. Pavic;P. Reynolds
本文对观众占用的土木工程结构（例如看台）的阻尼 2 自由度 (d.o.f.) 表示形式的模态特性进行了数值研究。特别是，它试图解释过去其他研究人员在这些结构被占用时与空置时进行的测量中自然频率和阻尼的一些奇怪变化的观察结果。针对两个单自由度的一系列频率、质量和阻尼系数的比率，对固有频率、振型、模态质量和阻尼比进行参数检查。串联的系统代表“人类”和“结构”振动行为。结果发现，阻尼 2-d.o.f.人群结构系统模型可以解释（1）阻尼增加，（2）额外的振动模式和（3）由于人群占用而在现实生活中的看台结构上观察到的固有频率的增加和减少。因此，基于等效 2-d.o.f 的装配结构简化动态响应分析的数学框架。人群与结构相互作用的动态建模可能是一个谨慎的前进方向。
This paper investigates numerically the modal properties of damped 2-degree-of-freedom (d.o.f.) representations of crowd-occupied civil engineering structures, such as grandstands. In particular, it attempts to explain observations of some curious changes in natural frequencies and damping in measurements made by other researchers in the past when such structures were occupied compared with when they were empty. Natural frequencies, mode shapes, modal masses and damping ratios are examined parametrically for a range of ratios of frequency, mass and damping coefficients of two single-d.o.f. systems connected in series representing the ‘human’ and ‘structural’ vibration behaviour. It is found that a damped 2-d.o.f. model of a crowd–structure system can explain (1) damping increases, (2) additional modes of vibration and (3) increases as well as decreases of natural frequencies observed on real-life grandstand structures due to crowd occupation. Therefore, a mathematical framework for simplified dynamic response analysis of assembly structures based on equivalent 2-d.o.f. dynamic modelling of crowd–structure interaction may be a prudent way forward.