基于振动模态分量的结构损伤定位方法  

Structural damage positioning method based on vibration modal component

作　　者：方治华[1] 杜晓旭 

机构地区：[1]内蒙古科技大学建筑与土木工程学院,内蒙古包头014010 [2]平顶山煤矿机械有限责任公司,河南平顶山467001

出　　处：《兰州理工大学学报》2013年第5期116-120,共5页Journal of Lanzhou University of Technology

基　　金：内蒙古自然科学基金(20080404MS0810)

摘　　要：三维实体结构振动时,结构上的任一点在三维空间各个方向均产生位移分量,振动模态也包含各个方向的模态分量.当结构损伤时这些模态分量会发生变化,但对损伤的敏感程度是不同的.基于这一特点,提出位移模态分量变化率、应变模态分量变化率和第一阶模态下的轴向位移差变化率3种针对三维实体结构的损伤标识量,并通过算例对损伤位置和损伤程度与3种标识量的关系进行计算分析,研究3种标识量对损伤位置的敏感程度.计算实例表明,3种结构损伤标识量都在损伤部位出现尖峰,可以用于损伤定位.3种损伤标识量中,位移模态分量变化率较小,对损伤的敏感程度不高;应变模态分量变化率较大,对损伤的敏感性较高;第一阶模态下的轴向位移差变化率最大,对损伤最敏感.When a three dimensional structure vibrates, every point in the structure will be displaced three-dimensionally. Vibration mode also includes modal components in itself in all directions. These modal components will change when the structure is damaged. But their sensitivity to the damage are different. According to this characteristics, three identification indexes of structure damage, such as the change rate of variation displacement modal component, the change rate of variation strain modal component, and the first-order change rate of axial displacement difference were presented. The calculation and analysis of the relationship between damage location and damage extent were carried out with these identification inde- xes by means of a calculation example. The sensitivity degree of three identification indexes to the damage location was studied. The calculation results showed that the peak appeared in these identification indexes spikes at the damage location, which could be used to determine the damage location. Among these three identification indexes, the change rate of variation displacement modal component was smaller at the damage location, so sensitivity degree of damage was lower. The change rate of variation strain modal compo- nent was larger at the damage location than the change rate of variation displacement modal component, but the sensitivity degree of damage was higher. The first-order change rate of axial displacement difference was the largest at the damage location, being the most sensitive damage.

关 键 词：振动模态分量 结构损伤 定位方法 敏感性 

分 类 号：TU312.3[建筑科学—结构工程]