中文摘要：

在单元应变模态差基础上,提出了基于单元广义应变差法的损伤识别方法,该方法由冲击荷载作用下的结构位移时程响应求出单元应变时程响应,对全部时间点单元应变时程响应绝对值求和后得出单元广义应变。采用结构损伤前后的单元广义应变差作为网格结构损伤定位的识别指标,并以损伤单元广义应变差值大小确定损伤程度。通过对一个典型管桁架的数值模拟表明：该方法只需要一次冲击荷载作用下的时程响应,就能够有效地识别出结构损伤定位及定量,且抗噪声能力优于现有的基于单元应变模态差的识别方法。

英文摘要：

Based on element modal strain approach, the damage identification method based on change of ele- ment generalized strain was presented. In this method, the element generalized strain was obtained by the summation of the absolute value of the strain time history curve,which can be deduced from the displace- ment time history response curve of the structure under impact load. Therefore the change of element gen- eralized strain was presented as a new dynamic indicator for damage location of the truss structure, and the damage degree was determined by the generalized strain change values. A numerical example for a tube truss was provided to verify the practicability of the method. The results indicated that this method only needs the time history response of the impact load at one time, which can effectively identify the damage positions and degrees. Moreover, the new method has stronger anti--noise ability than the conventional ele- ment strain modal method .