ERA方法在结构模态分析中的应用研究与案例分析

Research and case analysis on the application of the eigensystem realization algorithm( ERA) in modal parameter identification

本文简要介绍了结构模态时域分析方法中的EAR方法。并与随机减量法(RD)或NEx T数据处理方法相结合,对网架结构、钢筋混凝土框架结构和多跨钢筋混凝土桥梁结构的三个实际工程进行了整体或局部的模态参数测试、实施方案设计和有限元数值分析。通过研究比较得出,RD/ERA或NEx T/ERA可以有效地提高EAR方法的精度,EAR方法适用于多种结构类型,同时也验证了EAR方法的准确性和实用性,为ERA方法测试模态参数提供了实验理论依据和实际可行性实施方案。最后,讨论了EAR方法的局限与不足。

In this paper,an important time domain method for structural modal parameter identification,the eigensystem realization algorithm( ERA) is briefly introduced. With the method of Random Decrement Technique or Natural Excitation Technique for data processing,the model analysis,modal test scheme and FEM simulation for space truss,RC frame structure and multi span RC bridge are studied. Comparisons with results analysis,RD /ERA and NEx T / ERA have higher accuracy to the direct ERA method,and the EAR method is practical and accurate in real engineering. Finally,the limitation of EAR method is discussed.