基于信赖域算法的连续梁桥动力损伤识别

Damage Identification of Continuous Girder Bridge's Dynamic Behavior Based on Trust Region Algorithm

鉴于信赖域算法在求解非线性二次规划问题中具有良好的全局收敛特性,同时结合有限元模型修正技术,引入有效弹性模量损伤因子和损伤分布函数的概念,在Matlab编程环境下调用ANSYS有限元程序中的APDL语言进行桥梁空间结构的有限元建模,利用信赖域算法调整局部单元(组)的参数,通过连续损伤分布插值多项式拟合连续区段各单元(组)的损伤分布曲线,进而实现了对连续梁桥的动力损伤识别。数值算例表明该方法能准确、有效地判断桥梁结构的损伤发生、损伤区域以及损伤程度,同时该损伤识别过程可以结合二次精细划分单元(组)的方法来提高识别的精度和准确性。

In view of trust region algorithm has good global convergence for solving non-linear quadratic programming problem, the effective elastic module＇ s damage factor and the damage distribution function is introduced by FEM updating. FEM of bridge structure is modeled by calling the APDL language of ANSYS software＇ s subprogram in Matlab software＇ s environment. The parameters of some f/nite elements （element groups） are adjusted b.y using trust region algorithm, damage distribution curve of continuous region＇s finite elements （element groups） is fitted by continuous damage distribution interpolation polynomial, and identification of continuous girder bridge＇ s damage region and damage extent is realized. By a numerical example, it is suggested that the method can correctly and effectively estimate whether bridge structure occurs damage, damage region and damage extent, the precision and the accuracy can be improved by secondary dividing finite elements （element groups） .