基于灵敏度分析的机械系统损伤识别方法  

A Sensitivity Based Method for Damage Identification of Mechanical Structures

作　　者：刘济科[1] 李雪艳[1] 等 

机构地区：[1]中山大学应用力学与工程系，广州510275

出　　处：《机械科学与技术》2002年第3期456-459,共4页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家自然科学基金 (10 10 2 0 2 3 );广东省自然科学基金(0 0 1180 );广东省科技计划项目;高等学校优秀青年教师教学科研奖励计划资助

摘　　要：提出了一种基于振动灵敏度分析的机械系统损伤识别方法。该方法同时考虑了固有频率灵敏度和固有模态灵敏度 ,既可用于损伤定位 ,也能用于确定损伤大小 ,且对单个损伤和多个损伤情况都适用。为了提高识别的精度 ,考虑了二阶灵敏度。针对工程实际的需要 ,分析了不完备模态和模态测量误差对该方法识别精度的影响。算例表明 :本方法合理可靠 ,具有足够的精度。Detection, location and qualification of damage in mechanical structures is a very important topic of research, due to increasing demands for quality and reliability. The research effort to use changes in modal parameters (frequencies and modes) to identify structural damage in mechanical engineering has been increased during the last two decades. Since the modal parameters are affected by the mass and especially the stiffness, they can be used to monitor the structural integrity. Depending on the location and severity of damage, changes of modal parameters, especially natural frequencies and mode shapes, may be different from one mode of vibration to another. This fact implies that modal data are good candidates to localize damage qualitatively as well as quantitatively. The main advantage of using vibration monitoring as a damage indicator tool is due to its simplicity and cheapness. The aim of this paper is therefore to present a structural damage identification method for mechanical engineering structures. The sensitivity analysis of both natural frequencies and modal vectors is performed to locate the damage and obtain the extent of the damage. The present method is applicable for not only single damage but also multiple damages. The second order sensitivity is used to improve the identification accuracy. Furthermore, to meet the increasing demands for damage identification of actual engineering structures, the effect of incomplete modes and errors of measured modes on identification is also considered. An illustrative example is given to verify the present method and satisfactory results are observed.

关 键 词：灵敏度分析 机械系统 损伤识别 频率 模态 

分 类 号：TH113[机械工程—机械设计及理论]