基于局部静力测试的约束子结构修正法

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振动与冲击 ›› 2012, Vol. 31 ›› Issue (9) : 39-43.

论文

基于局部静力测试的约束子结构修正法

杨秋伟1, 刘济科2

作者信息 +

Isolated substructure model updating based on local static test

Yang Qiu-wei1, Liu Ji-ke2

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文章历史 +

摘要

针对局部子结构为修正对象的情况，提出只利用整体结构中局部子结构部分的静力位移即可精确修正子结构模型的约束子结构方法。首先利用静力测试获得局部子结构所对应的局部柔度矩阵，通过在子结构边界处施加虚拟固定支座，把子结构从整体结构中隔离出来成为约束子结构，同时构造出该约束子结构相应的柔度矩阵。然后利用柔度扰动新方法优化修正约束子结构，即等同于修正相应的子结构模型，从而可对该子结构的损伤状况作出评估。以一个平面桁架结构为例对所提方法进行了验证。结果表明，所提方法合理可靠，计算简单快捷且精度良好。

Abstract

For large-scale structures, measurement and identification for a whole structure are very difficult and the accuracy of the estimates is rarely reliable. In general, only some local substructure model is important and it is not necessary to update the whole structure. From such a viewpoint, this paper studied the isolated substructure method for model updating and damage detection. It aims at updating local substructure element stiffness by using the static response at the corresponding substructure location of the whole structure. Firstly the isolated substructure is formed by applying virtual fixed support (numerically and not physically) on the substructure boundary, to obtain the local flexibility matrix of the isolated substructure. Then the new flexibility perturbation method is used to modify the model of the isolated substructure, which can accurately compute the stiffness modification coefficients only by simple computation without any higher-order approximation or iteration. A plane truss structure is analyzed as a numerical example to verify the present method. Results show that the substructure could be updated successfully by using the static displacement response at the corresponding substructural location even with 3% noise.