木梁基于曲率模态技术的损伤识别

Damage recognition of timber beam based on curvature modal technology

利用有限元分析软件建立了木梁的损伤模型,获取了不同损伤参数的曲率模态;基于结构动力学中梁自由振动的理论,推导了木梁基于曲率模态的损伤程度判定理论;对人工模拟的损伤木梁进行了模态试验。结果表明:曲率模态对损伤识别非常敏感,损伤位置可通过曲率模态图的突变判定,损伤程度可以根据突变程度判定;模态分析试验结果与有限元分析结果吻合较好;有限元算例和模态试验验证了损伤程度判定理论公式的适用性,采用曲率模态技术对木梁进行损伤检测是有效可行的。

The damage model of timber beam was established by finite element analysis software,and the curvature modes of different damage parameters were obtained.Based on the theory of free vibration of beam in structural dynamics,the damage degree judgment theory of timber beam based on curvature mode was deduced.The mode test of the damaged timber beams by artificial simulation was carried out.The results show that curvature mode is very sensitive to damage recognition,the damage location can be accurately determined by the sudden change of the curvature mode diagram,the damage degree can be determined by the sudden change degree.The curvature modes obtained from the modal test are agree with those obtained from the finite element analysis.The applicability of the theoretical formulas for judging damage degree is verified by finite element examples and modal tests,it is feasible and effective to use curvature mode technology to recognise damage of timber beams.