基于模态柔度理论的结构损伤诊断试验研究

发布时间：2019-08-08 19:35

【摘要】：利用多参考点脉冲锤击法的输入输出动力信号获取结构的模态柔度,可以对结构进行损伤识别,设计了一根钢筋混凝土简支梁和一块钢-混凝土组合板的静动力试验.对不同损伤状态下的简支梁和组合板进行了动力测试,得到其模态柔度矩阵,并用来预测结构在荷载作用下的位移.简支梁试验结果表明,随着损伤程度的加深,结构自振频率降低,阻尼比增大,柔度增大,但自振频率只能判断结构损伤的出现,模态柔度则能够综合全面地反映钢筋混凝土简支梁结构的损伤位置和损伤程度.组合板试验表明,在线弹性状态下,动力测试与静力测试获得的模态柔度矩阵相差很小.设计了支座刚度变化、连接件损伤和横向支撑破坏这3种损伤工况,并用这3种工况来模拟实际桥梁结构可能出现的损伤状况.通过对比结构损伤前后的模态柔度位移信息,成功实现了组合板的损伤识别.
[Abstract]:The modal flexibility of the structure can be obtained by using the input and output dynamic signals of the multi-reference point pulse hammering method, and the damage identification of the structure can be carried out. The static and dynamic tests of a simply supported reinforced concrete beam and a steel-concrete composite slab are designed. The dynamic tests of simply supported beams and composite plates under different damage conditions are carried out, and the modal flexibility matrix is obtained, which is used to predict the displacement of the structure under load. The test results of simply supported beam show that with the deepening of damage degree, the natural vibration frequency of the structure decreases, the damping ratio increases and the flexibility increases, but the natural vibration frequency can only judge the occurrence of structural damage, and the modal flexibility can comprehensively reflect the damage location and damage degree of reinforced concrete simply supported beam structure. The composite plate test shows that there is little difference between the modal flexibility matrix obtained by the dynamic test and the static test in the on-line elastic state. Three kinds of damage conditions, such as bearing stiffness change, connector damage and transverse support failure, are designed, and these three working conditions are used to simulate the possible damage conditions of the actual bridge structure. By comparing the modal flexibility displacement information before and after structural damage, the damage identification of composite plate is successfully realized.
【作者单位】：湖南大学土木工程学院;
【基金】：国家自然科学基金青年基金资助项目(51208190) 湖南省自然科学基金青年基金资助项目(12JJ4053) 高校博士点基金新教师基金资助项目(20120161120028) 湖南大学青年教师成长计划资助项目~~
【分类号】：TU317

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