质量分布对结构动力特性的影响研究

A Study of Dynamic Characteristics of Structures Influenced by Mass Distribution

为研究框架结构上楼层质量分布对结构动力特性的影响,推导考虑几何刚度的框架柱单元刚度矩阵,建立了考虑质量分布对结构模态特性影响的有限元分析模型.分析结果表明结构上楼层分布的质量对结构固有频率的改变不可忽略,同时楼层分布质量引起结构的侧向刚度下降也会导致其固有频率下降,本研究所采用的分析模型对框架结构的地震响应分析具有参考价值.

This paper targets at studying the dynamic characteristics of frame structure influenced by its floor mass distribution.The stiffness matrix of the frame column considering the geometric stiffness is derived,and the analysis model considering the influence of the mass distribution on the modal properties of the structure is established based on then finite element method.The analysis results show that the mass distributed on the floor of frame structure could not be ignored for the change of the natural frequency of the structure; furthermore,the lateral stiffness of frame structure would be decreased by the mass distributed on the floor,resulting in a decline in its natural frequency.The analysis model used in this study is valuable for the seismic response analysis of the frame structure..