裂纹损伤对塔壳结构动态特性的影响研究  

Crack detection based on vibration signals in tower structures

作　　者：陈玲莉 彭海强[1] 陈振茂[1] 

机构地区：[1]西安交通大学,西安710049

出　　处：《应用力学学报》2011年第3期299-303,329,共5页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(50977070)

摘　　要：基于数值方法研究裂纹损伤对塔式壳体结构动态特性的影响。建立了等截面直立塔壳结构有限元模型,采用刚度下降法模拟不同程度受损单元,计算了无损和不同损伤工况下（耳式支座与塔体角焊缝处环向裂纹损伤）,结构的固有振动特性和脉动风载荷作用下结构的动态响应。结果表明：结构振动信号可以反映塔壳结构局部不同程度损伤的影响,裂纹损伤对固有频率影响较小,最大20%损伤对固有频率的减小约为7%~8%;对模态振型影响较大,尤其在高阶（如15阶频率）上可能出现新的振型;对位移响应、动应力影响最为明显。This article is devoted to the method of crack detection based on vibration signals in tower structures.We establish the analysis model for the erect tower structures of uniform cross-section without-crack and with crack,respectively;and then numerically simulate the inherent vibration characteristics of the tower structures under the cases of the different cracks（Here,the crack means the circumferential one between lugs-stand and fillet weld of the tower.） In addition,the vibration response is examined for the tower structures with different cracks under the same fluctuating wind loading.Our investigation shows that the crack detection in the tower structures based on vibration signals is a simple,effective and practical method.Therefore,it is of significance for the presented method to inspect the security of structures under the case of online service in the engineering applications.

关 键 词：塔式结构 裂纹损伤 脉动风载 振动特征 

分 类 号：O327[理学—一般力学与力学基础]