一种模拟动力学边界条件的环境振动试验方法研究

目的提高环境振动试验的可靠性。方法以某典型钛合金蜂窝夹芯壁板试验件为例,提出一种模拟试验件动力学边界条件的试验方法,在试验件周围引入弹性连接件,再通过刚性转接工装与振动台台面连接,以试验件在试验安装状态下的共振频率及振型节线位置为优化目标,以弹性连接件的外形尺寸及厚度为优化变量,对弹性连接件进行优化设计,从而模拟试验件真实的动力学边界条件。结果弹性连接件的优化设计使得试验件在试验安装状态下前两阶共振频率与试验要求相差小于8%,而且振型节线位置与试验要求基本重合,达到了模拟试验件真实动力学边界条件的设计目标。结论对于壁板类试验件,在传统刚性夹具的基础上引入弹性连接件的试验方法,可以较好地模拟试验件真实动力学边界条件,提高环境振动试验的可靠性,并且这种方法对试验费用及试验周期影响较小,具有良好的工程应用前景。

Dynamic Simulation of Boundary Conditions in Environment Vibration Experiment

Objective To improve the reliability of environment vibration experiment. Methods A typical titanium alloy honeycomb sandwich panel test article was taken as an example. A method for simulating dynamic boundary conditions was proposed. In this method, the test article was connected with the elastic connectors around, and then was connected with the vibration table through a rigid transfer tool, to simulate the dynamic boundary conditions of the test article, with modal frequency and mode shape of the elastic connector as the optimization targets, and with the outline dimension and thickness of the elastic connector as optimization variables. Results The optimization of the elastic connector made the difference between the first two modal frequency of the test article and the test requirements be less than 8%. Location of nodal line of modal shape were coincidence with the test requirement. The design objective for the actual dynamic boundary conditions of simulating the test article was realized. Conclusion The method which introduces elastic connector based on the traditional rigid fixture could simulate dynamic boundary conditions of the test article well, and improve reliability of environment vibration experiment. At the same time, the method has little influence on the expenses and the period of the experiment, which would have good engineering application prospects.