结构动力学应用中若干基本概念的研究  

A study on some basic concepts in the application of structural dynamics

作　　者：张开银[1] 孙齐 熊驷东[1] 蒋紫玲 ZHANG Kaiyin;SUN Qi;XIONG Sidong;JIANG Ziling(School of Naval Architecture,Ocean and Energy Power Engineering,Wuhan University of Technology,Wuhan 430063,China)

机构地区：[1]武汉理工大学船海与能源动力工程学院,武汉430063

出　　处：《振动与冲击》2024年第4期297-302,共6页Journal of Vibration and Shock

基　　金：国家自然科学基金(51809209)。

摘　　要：结构动力特性被广泛应用于结构振动控制、结构可靠性设计和健康监测,由此涉及到一些动力学基本概念的理解问题尚待深入探讨。采用一简支梁横向振动算例以及分别通过模态位移法和模态加速度法对多自由度系统的响应振幅进行分析计算,探讨结构位移响应与第一阶固有频率的关系、结构各阶位移模态的贡献与模态应变能的关系。基于模态正交性,通过分析多自由度振动系统的位移响应,论述了系统共振的必要条件,即在保证系统振动频率(某阶固有频率)等于激励频率的同时,其位移响应还应呈现出相应模态的形态;实现多自由度系统纯模态共振,可用于精确识别结构的模态参数。Structural dynamic characteristics are widely used in structural vibration control,structural reliability design,and health monitoring,from which some basic concepts of dynamics need to be further discussed.An example of transverse vibration of a simply supported beam was used to analyze and calculate the response amplitude of a multi-degree-of-freedom system by a modal displacement method and a modal acceleration method,respectively.The relationship between structural displacement response and first-order natural frequency and the relationship between structural displacement mode contribution and modal strain energy were discussed.Based on the modal orthogonality,by analyzing the displacement response of the multi-degree-of-freedom vibration system,the necessary conditions of the system resonance were discussed,that is,while ensuring that the vibration frequency of the system(a certain natural frequency)is equal to the excitation frequency,the displacement response should also show the corresponding modal shape,and the pure modal resonance of the multi-degree-of-freedom system can be used to accurately identify the modal parameters of the structure.

关 键 词：结构动力特性 固有频率 模态分析 多自由度系统 共振 纯模态 

分 类 号：U466.1[机械工程—车辆工程]