The Study On The Test Conditions Of The Typical Structure Based On The Equivalence Of Stress Response For The Triaxial And Uniaxial Random Vibration

The vibration test is a necessary method to identify whether the structure or equipment can withstand the expected vibration environment. Compared with the uniaxial vibration test, the triaxial vibration test is gaining extensive attention due to the convenient and fast accurate simulation of the actual vibration environment. Triaxial vibration table also has gradually appeared in recent years. However, due to its late start, there is no unified standard for triaxial vibration test. Aiming at the equivalence of the stress response of triaxial vibration to that of uniaxial vibration, this paper cuts the load spectrum of the triaxial vibration and studys the conditions of triaxial vibration test. Details are as follows:Firstly, the studies of the related theory of basic mechanics and the technology of the finite element simulation are described briefly, so is the optimization function of ANSYS Workbench software. The examples of modal analysis, random vibration analysis and load optimization analysis with ANSYS Workbench, not only verify the accuracy of this article using the software, but also provide a theoretical basis for subsequent analysis.Secondly, the research on triaxial random vibration test condition of simple structure is proceeded. By means of the stress comparison of the simple structure of the cantilever beam under uniaxial and triaxial random vibration response analysis, the conclusion that the stress of triaxial random vibration response is larger than any other uniaxial vibration response is drawn. Inputting load spectrum of the triaxia vibration is cut by using the load optimization analysis, which is followed by the analysis of the relationship of the ratio of root mean square value of load spectrum before and after the cut of the equivalent stress, providing the basis for the subsequent finite element analysis.Thirdly, the collaboration simulation of CAD/CAE and the influence of fixturet on the modal vibration of the system are analyzed. Because the part-cabin structure is very complex in this paper, when proceeding the finite element analysis, it is necessary to simplify handling in the 3D drawing software of Pro/E, and then import the model tothe finite element analysis software of ANSYS Workbench. So this article discusses the CAD/CAE collaborative modeling and simulation.And the influence of fixtures on the test of the whole system are analyzed theoretically, which provides guidance for the analysis of characteristics of fixtures on the vibration of the system.Finally, the triaxial random vibration test conditions of the typical part-cabin structure is studied. the finite element model of the part-cabin structure is presented at first, and the influence of the vibration characteristic of the fixture on the compartment system is analyzed, then followed by the the research of the stress comparison of the part-cabin under uniaxial and triaxial random vibration response analysis. And based on load optimization method, the load spectrum of triaxial random vibration test is given out by tailoring triaxial the loading.