摘要
本文给出了结构动态应变/应力分析的模态分析原理和方法。其基本思想是:结构在承受动态载荷的作用时,其应变场可用所谓“固有的模态应变场”按某种比例的叠加来表达。固有模态应变场(简称应变模态)对应于结构的固有振动位移模态,并取决于结构的动特性。根据这一思路导得的应变响应预测模型以及固有应变模态和相应的模态参数识别方法,我们称之谓应变模态分析。按本文发展的方法,可以通过电阻应变计直接测量应变频响函数,然后用曲线拟合法求取应变模态及模态参数。给出的实例说明,应变模态对于结构的局部变化较为敏感。
This paper presents the principle and Techniques of slain/stress modal analysis. The basic idea is that the strain field response can be regard as a superposition of the so called strain modes multiplied by corresponding time-dependent modal coordinate. The strain mode and the associate vibration displacement mode depend to the characterislics of structure, According to this idea, the strain response prediction modal model and the associate parameter identification Techniques are developed. The frequency response function of strain can be measured directly by slrain gauges, then the strain modes and the modal parameters are identifed by curve fitting. As an example, the strain modes of a cantilever with a crack are analyzed. The results show that slrain mode shape is more sensitive to the crack than displacement mode.
出处
《振动与冲击》
EI
CSCD
北大核心
1992年第4期15-22,共8页
Journal of Vibration and Shock
基金
自然科学基金
