典型结构三轴与单轴随机振动应力响应等效的试验条件研究

发布时间：2018-03-02 19:46

本文选题：单轴振动　切入点：三轴振动　出处：《西安电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：振动试验是鉴定结构或仪器设备能否承受预计的振动环境的一种必要手段。与单轴振动试验相比,三轴振动试验由于能准确快速方便的模拟实际振动环境而受到广泛重视,近年来三轴振动台也逐渐问世。然而由于其起步较晚,目前无统一的三轴振动试验标准。本论文从使三轴振动的应力响应与单轴振动应力响应等效为出发点,裁剪三轴振动的载荷谱,研究三轴振动的试验条件,具体完成工作如下:首先是基础力学的相关理论以及有限元仿真技术的研究,并且简要叙述了ANSYS Workbench的优化功能。通过模态分析算例、随机振动分析算例和ANSYS Workbench的载荷优化分析算例验证了本文使用软件的正确性,为后续分析提供了理论基础。其次是简单结构的三轴随机振动试验条件的研究。对简单悬臂梁结构进行单轴与三轴随机振动的应力响应对比分析,得出三轴振动比任一单方向的单轴振动响应应力都大的结论;运用载荷优化分析,裁剪三轴振动的输入载荷谱,并分析裁剪前后载荷谱的均方根值的比值与裁剪前后等效应力的均方根值的比值的关系,为后续的有限元分析提供依据。之后是CAD/CAE协同仿真以及夹具对系统模态振动的影响的研究。由于本论文舱段模型较为复杂,有限元分析时需要先在三维绘图软件Pro/E中进行简化处理,然后导入ANSYS Workbench中进行有限元分析,因此本文讨论了CAD/CAE的协同建模仿真。同时从理论上分析了夹具对整个试验系统的影响,为下文分析夹具对系统的振动特性的影响提供了指导。最后是典型舱段结构的三轴随机振动试验条件的研究。给出了舱段结构的有限元模型,分析了夹具对舱段系统的振动特性的影响,然后对舱段结构进行单轴与三轴随机振动响应的应力响应对比分析,基于载荷优化方法,裁剪三轴同时加载的载荷谱,给出三轴随机振动试验的裁剪方案。
[Abstract]:Vibration test is a necessary means to determine whether the structure or equipment can withstand the predicted vibration environment. Compared with the uniaxial vibration test, triaxial vibration test is paid more and more attention because of its ability to simulate the actual vibration environment accurately, quickly and conveniently. In recent years, triaxial vibration table has gradually come out. However, due to its late start, there is no unified standard of triaxial vibration test. This paper starts from the point of view of making the stress response of triaxial vibration equivalent to that of uniaxial vibration. The load spectrum of triaxial vibration is cut and the experimental conditions of triaxial vibration are studied. The work is as follows: firstly, the related theory of basic mechanics and finite element simulation technology are studied. The optimization function of ANSYS Workbench is briefly described. The correctness of the software is verified by the modal analysis example, random vibration analysis example and load optimization analysis example of ANSYS Workbench. It provides a theoretical basis for further analysis. Secondly, the experimental conditions of triaxial random vibration of simple structures are studied. The stress responses of simple cantilever structures under uniaxial and triaxial random vibration are compared and analyzed. It is concluded that the response stress of triaxial vibration is greater than that of any uniaxial vibration, and the input load spectrum of triaxial vibration is cut by using load optimization analysis. The relationship between the ratio of the root mean square value of the load spectrum before and after cutting and the ratio of the root mean square value of the equivalent stress before and after cutting is analyzed. It provides the basis for the subsequent finite element analysis. Then there is the study of the CAD/CAE co-simulation and the influence of the fixture on the modal vibration of the system. Because of the complexity of the cabin model in this paper, The finite element analysis needs to be simplified in 3D drawing software Pro/E, and then imported into ANSYS Workbench for finite element analysis. Therefore, this paper discusses the collaborative modeling and simulation of CAD/CAE, and theoretically analyzes the influence of fixture on the whole test system. It provides guidance for analyzing the influence of fixture on the vibration characteristics of the system below. Finally, the experimental conditions of triaxial random vibration of typical cabin structure are studied. The finite element model of cabin structure is given. The influence of fixture on the vibration characteristics of cabin system is analyzed, and then the stress response of single-axis and three-axis random vibration response of cabin structure is compared and analyzed. Based on the load optimization method, the load spectrum of triaxial loading at the same time is cut. The cutting scheme of triaxial random vibration test is given.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB534

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