【摘要】 频率和振型是反应结构动力特性的主要模态参数,文中对损伤结构的频率和振型进行了研究。通过实测损伤结构的频率和振型,利用矩阵理论修正理论有限元模型,使之与实测损伤结构的频率和振型一致;将修正的理论有限元模型表达成单元刚度矩阵与损伤因子的线性组合,把损伤识别问题转化为组合系数的识别问题。给定损伤因子的合理取值范围,用优化方法求解损伤因子。通过对十跨桁架结构的数值仿真,仅用结构的前5阶频率和振型就能很好的识别结构的损伤,且该方法不需要对实测振型进行归一化处理,具有较强的实用性。更多还原

【Abstract】 The frequency and vibration mode were the main modal parameters representing dynamic characteristics of structure,and the frequency and vibration mode of the damaged structure were studied in this paper. First,through measuring the frequency and vibration modes of the damaged structure,a correction theory of matrix was used was used to modify the finite element model,which was consistent with the frequency and vibration modes measured from the damaged structure. Secondly,the finite element model( FEM) of the revision theory can be expressed by a linear combination of the element stiffness matrix and the damage factor. The damage identification problem transformed into the solution of the combination coefficients. Next,the range of reasonable values of damage factors was given and the damage factors could be solved by the optimization method. Through the numerical simulation of a ten-span truss structure,the structural damage could be identified significantly by merely using frequencies and vibration modes of the first five orders. Furthermore,the method does not need to normalize the measured vibration modes,but has strong applicability.更多还原