Abstract:

A new method of isolation substructure was proposed to update a local substructure based on local vibration test responses, aiming to solve the problems of the excessive identification parameters and low efficiency applied in large complex structure model updating. The method utilized the local structure's vibration test responses to construct the isolation substructure, in order to separate the substructure from the whole and constituted a simply independent structure, which could weaken the influence of the whole effectively. Then, the objective substructure was updated based on the responses of isolation substructure. Finally, a T shaped weld steel tube and the launch platform model were given to prove the effectiveness of the method. The results show that the proposed method contains fewer elements and can be updated easier with high efficiency, and it is well suitable for model updating of such large complex structure.

Key words: vibration test response, isolated substructure, model updating, objective function

摘要：

针对大型复杂结构模型修正中待识别参数过多、修正效率低等问题，提出一种基于局部振动测试的约束子结构模型修正方法。首先，利用子结构部分的振动测试响应构造约束子结构，从而将子结构从整体结构中隔离出来，形成独立简单的结构，有效地隔绝整体结构对子结构的影响。然后，基于构造的约束子结构响应数据，直接对待修正的目标子结构进行模型修正。最后，以一个T形钢管焊接结构和某发射台骨架为例，对所提方法的有效性进行了验证分析。结果表明，该方法不仅能够减少待识别参数，简化修正过程，而且修正效率及精度也较高，为大型复杂结构的模型修正提供了一种新思路。

关键词: 振动测试响应, 约束子结构, 模型修正, 目标函数