曹登庆, 张笑云, 王逸龙. 基于假设模态加权的全局模态提取方法及其应用. 力学与实践, 2023, 45(4): 866-873. DOI: 10.6052/1000-0879-22-704
引用本文: 曹登庆, 张笑云, 王逸龙. 基于假设模态加权的全局模态提取方法及其应用. 力学与实践, 2023, 45(4): 866-873. DOI: 10.6052/1000-0879-22-704
Cao Dengqing, Zhang Xiaoyun, Wang Yilong. Global mode extraction method based on assumed mode weighting and its application. Mechanics in Engineering, 2023, 45(4): 866-873. DOI: 10.6052/1000-0879-22-704
Citation: Cao Dengqing, Zhang Xiaoyun, Wang Yilong. Global mode extraction method based on assumed mode weighting and its application. Mechanics in Engineering, 2023, 45(4): 866-873. DOI: 10.6052/1000-0879-22-704

基于假设模态加权的全局模态提取方法及其应用

GLOBAL MODE EXTRACTION METHOD BASED ON ASSUMED MODE WEIGHTING AND ITS APPLICATION

  • 摘要: 假设模态法在单一梁、杆、索、板等柔性结构动力学建模中有广泛应用,但在处理组合结构振动问题时,常常因无法反映各部件之间的耦合作用使其应用受限。通过假设模态建立组合结构的近似动力学模型,利用近似模型求得系统的固有频率和相应的特征向量,据此可以有效地获得系统的全局模态。本文以跨中带有多个弹性支撑的简支梁为例,通过假设模态加权来提取系统的全局模态,从而建立系统的动力学模型。对系统进行固有特性分析的结果表明,通过假设模态加权可以方便地获得系统的全局模态;对系统动态响应分析的结果表明,采用本文提出的全局模态建立的非线性动力学模型可以有效地反映系统的非线性动力学特性。

     

    Abstract: The assumed mode method is widely used in the dynamic modeling of single flexible structures such as beams, bars, cables and plates. However, its application is limited when dealing with the vibration problems of combined structures because it cannot reflect the coupling between components. The approximate dynamic model of the combined structure can be established by using the assuming modes, and then the natural frequencies and corresponding eigenvectors of the system can be obtained by using the approximate model. Based on this approach, the global modes of the system can be obtained effectively. In this paper, a simply supported beam with multiple elastic supports in the middle span is taken as an example, and the global modes of the system are extracted by assuming mode weighting, so as to establish the dynamic model of the system. The results of the intrinsic characteristics analysis of the system show that the global mode of the system can be easily obtained by assumed model weighting. The results of dynamic response analysis of the system show that the nonlinear dynamic model based on the proposed global mode can effectively reflect the nonlinear dynamic characteristics of the system.

     

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