结构损伤识别的非线性解析法

本文在直接解析法的基础上,进一步提出结构损伤识别的非线性解析法.它与直接解析法不同之处是:考虑了频率和振型对损伤参数的二阶偏导数项,以此构造损伤参数为未知量的超定非线性方程组.求解该方程组可以一次性得到全部损伤参数值.本方法不仅具有直接解析法的优点,而且由于构建方程组时增加了损伤参数的二次项,极大地提高了损伤识别的精度.最后,通过对一个五层框架结构进行数值模拟分析验证了该方法的可行性,同时经过比较计算结果表明:在损伤识别中,非线性解析法在精度及节省计算工作量上明显优于直接解析法.

Nonlinear Analytical Method for Structural Damage Identification

Based on the directly analytical method for structural damage identification,the nonlinear analytical method was presented.The difference of these two methods is that on taking second order patial derivatives of frequency and mode shape with respect to damage parameters into account,the nonlinear analytical method constructs overdetermined nonlinear equations with damage parameters as unknowns the present method can diagnose the number,the locations and the severity of damage at the same time.The present method not only has the virtues of nonlinear,but also considers the quadratic item of damage parameters,and then,enhances the identifying precision.A numerical simulation example of a five-storey RC frame structure shows the feasibility of present method,synchronously,and to validate that the nonlinear method bether than the linear one on precision and computing time.