基于模态参数灵敏度分析的结构损伤识别研究  

Identification of structural damage based on the sensitivity analysis of modal parameters

作　　者：闫天红[1] 王凤山[2] 姜民政[1] 周国强[1] YAN Tian-hong;WANG Feng-shan;JIANG Min-zheng;ZHOU Guo-qiang(School of Mechanical Science and Engineering,Northeast Petroleum University,Daqing 163318;Production Engineering Research Institute,Daqing Oilfield Co.,Ltd.,Daqing 163712)

机构地区：[1]东北石油大学机械科学与工程学院,黑龙江大庆163318 [2]大庆油田有限责任公司采油工程研究院,黑龙江大庆163712

出　　处：《机械设计》2019年第12期79-83,共5页Journal of Machine Design

摘　　要：结构损伤通常以结构中刚度损失为特征。结构的损伤会引起结构参数的改变,结构参数变化会导致结构模态参数(固有频率、振型)的变化,因此寻求结构损伤与结构模态参数之间的关系十分重要。文中根据结构振动特征方程,推导了结构模态参数对结构参数改变的灵敏度表达式,建立了结构模态参数对以单元刚度为特征的结构损伤识别关系式,识别结构损伤的位置和损伤程度。文中制作了无损伤、有损伤3根悬臂梁钢板试件,测取试件结构固有频率与振型,根据无损伤试件结构图,建立了有限元模型,计算其结构固有频率与振型。将无损伤试件测得的模态参数作为有限元模型修正依据,并用两种损伤条件下测得的数据修正无损伤的有限元模型,将单元刚度作为修正参数,应用灵敏度方法来识别悬臂梁钢板试件损伤的位置和程度,其结果与实际基本一致,证明了方法的有效性。Structural damage is usually characterized by loss of stiffness in the structure.It often causes the structural parameters to change,which will subsequently lead to the change in structural modal parameters(natural frequency and modal shape).Therefore,it is important to find out the relationship between structural damage and structural modal parameters.In this article,according to the equation of structural vibration characteristics,the sensitivity expression of the structural modal parameters to the change of structural parameters is derived,and the relationship between the structural modal parameters and the identification of structural damage characterized by the element stiffness is worked out,in order to identify the location and degree of structural damage.Based on this,three Cantilever-beam steel-plate specimens with and without damage are made,so as to measure the natural frequency and modal shape of the structural specimen.According to the structural diagram of the non-damage specimen,the finite-element model is set up,and its natural frequency and modal shape are computed.The modal parameters obtained from the non-damage specimen provide basis for the updating of the finite-element model.The data obtained under the two circumstances is used to update the finite-element model of the non-damage specimen.The element stiffness is used as the updating parameter.The location and degree of specimen damage are identified with the aid of the sensitivity method.The results are basically consistent with the actual situation,which proves that the method is effective.

关 键 词：振动测试 模态分析 模型修正 灵敏度分析 损伤识别 

分 类 号：P752[天文地球—海洋科学]