单元模态应变能法在输电铁塔损伤识别中的应用

输电塔结构在灾害中发生倒塌的现象时有发生,故而对输电塔结构进行健康监测具有重要的实际意义。介绍了单元模态应变损伤指数(EMSDI)在结构损伤识别中的表达式,并将其应用于输电铁塔模型试验中。采用单元形函数代替原有模态曲率计算方法,可有效降低计算单元模态应变能的计算误差,从而增加了识别的准确性。在输电铁塔仿真模拟和试验中,对该识别方法的准确性和可靠性进行了验证。实例表明:单元模态应变损伤指数法能够准确地识别出结构的损伤位置,并可在某种程度上反映出损伤程度,可以应用到实际输电塔结构损伤识别中。

Application of Element Modal Strain Energy Method in Damage Identification of Transmission Tower

Transmission towers have attracted more and more attention,for the phenomenon of their collapse existing widely in natural disasters.So it is significant to monitor the healthy condition of transmission towers.This paper introduces the expression of element modal strain damage index(EMSDI) in the field of damage identification,and further applies it into the model test of a transimission tower.The element shape function takes the place of the original calculation mehod of modal curvature,which effectively decreases the error in computing element modal strain energy and increases the accuracy of damage identification.In both the transimission tower numerical simulation and experiment,the validity and reliablity of this damage detection method are verified.The test case shows that the difference of EMSDI can exactly find the damage location and reflect damage extent in some degree.It can be used in damage identification of transmission towers.