基于应变模态差的索桁架-索网结构损伤识别
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（辽宁工程技术大学建筑工程学院， 阜新 123000）
［摘要］应变模态差法多用于刚性结构的损伤识别，而较少用于柔性结构。索桁架-索网结构是柔性组合结构，该结构通过预应力索提供刚度，结构损伤的主要因素是索的损伤和预应力损失。基于有限元模态分析提取结构损伤前后的应变模态差作为损伤识别指标，应用应变模态差法对索桁架-索网结构进行计算分析。结果表明：索单元发生损伤后，通过应变模态差能够准确地识别索不同位置的损伤，同时对小损伤(损伤程度10%)较敏感；得出应变模态差与损伤程度的关系曲线，该曲线在不同工况下能够很好地判断索单元损伤程度；利用应变模态差能够识别出索的预应力损失的位置，并可大致判断损失程度；验证应变模态差损伤识别方法可以较好地用于索桁架-索网结构的损伤识别。［关键词］索桁架-索网; 应变模态差; 损伤识别; 预应力索中图分类号：TU398+.9 文献标识码：A 文章编号：1002-848X(2016)07-0099-05
Damage identification of cable truss-cable net structure based on strain mode differenceYin Zhixiang, Xu Zongmin(Institute of Architecture and Civil Engineering, Liaoning Technical University, Fuxin 123000, China)Abstract: Strain mode difference method is usually used for the recognition of the rigid structure damage but is rarely used for the flexible structure. Cable truss-cable net structure is a flexible composite structure which provides stiffness through prestressed cable and the main factors of structural damage are cable damage and prestress loss. The strain mode differences before and after structural damage were extracted as damage identification index based on finite element mode analysis, and strain modal differential method was used to carry out calculation and analysis on cable truss-cable net structure. Results show that the cable damages in different locations can be accurately identified through the strain mode difference when the cable damage occurs, and meanwhile, it also shows that the method is more sensitive to small injury (damage degree of 10%); the relation curve between the strain mode difference and the damage degree is drawn and the curve can well judge damage degree of cable element under different working conditions; strain mode difference method can be used to identify the location of the prestress loss of cable and can roughly judge the loss degree; it verifies that the strain mode difference based damage identification method can be well applied to the damage identification of cable truss-cable net structure.Keywords: cable truss-cable net; strain mode difference; damage identification; prestressed cable
作者简介：殷志祥，博士，教授，Email:lntuyzx@163.com。
