测量模态不完整情况下空间网架结构的损伤识别

空间网架结构杆件数量庞大,自由度数目很多,要测得完整的模态数据有很大的困难。如何利用有限的测量信息对结构的损伤情况进行判断是一个实际的问题。对测量自由度不完整情况下网架的损伤识别,提出了两步法:第一,将测量的振型通过动力扩阶方法得到完整振型,利用模态应变能进行疑似损伤杆件判断;第二,利用最小二乘支持向量机对第一步判断的疑似杆件进行进一步的杆件损伤定位和定量。以一个空间网架结构为模型进行了数值模拟验证,结果表明对于测量模态不完整的网架结构损伤识别本文提出的方法是有效的。

Damage identification of space truss with incomplete measured data

It is difficult to get the complete modal data of space trusses with many elements and degrees of freedom. How to detect the damage of a space truss with incomplete modal data is a practical problem. A two-step method is presented for space truss damage identification with incomplete measured data. The incomplete mode shape is expanded using a dynamic model expansion technique and the possible damage elements are identified by use of model strain energy. Then, the Least Squares Support Vector Machine (LS-SVM) is used to access damage locations and damage quantities. A space truss structure is analyzed to verify the presented method, and the results show that the method is efficient for space truss damage identification with incomplete measured data.