装配式钢桁桥动力特性的有限元分析与试验

Finite Element Analysis and Experimental Study on Dynamic Characteristics of Prefabricated Steel Truss Bridge

固有频率和振型是反映结构动力特性的重要模态参数,其对于结构优化设计、结构动力学分析及使用状态的评估均具有重要意义。基于有限元软件ANSYS建立了某型装配式钢桁桥的三维空间有限元分析模型,并采用子空间法对其进行了模态分析,得出了相应的模态参数和振型。为验证数值计算结果,基于环境激励的谱分析方法对该桥进行了实装模态测试与分析。比较表明,有限元分析结果和实装测试结果吻合较好,验证了本文计算方法的可信性。在此基础上,结合有限元分析和实装测试结果,对该桥的自振特性进行了分析,为该类桥的动力特性分析提供了参考。

Natural frequencies and mode shapes, the invariable modal parameters reflecting the whole properties of a structure, are great significance for structural design validation, dynamics model constitution and bridge condition assessment. In this paper, a 3-dimension finite element model for a prefabricated steel truss bridge is established in detail and model analysis is carried out with ANSYS. The dynamic char- acteristics of the bridge are calculated by use of subspace iteration method. In order to validate the simula- tion results, the modal test method based on environment excitation is used, and the modal test of the pre- fabricated steel truss bridge is completed by configuring the test equipment sensors and analytic software. The result shows that calculation and testing well coincident and hence proves the reliability of this method- ology. All of these provide reference for dynamic analysis of similar equipment.