基于冲击响应谱的高速火箭橇滑轨路谱分析

为了评估高速火箭橇滑轨的平顺性,提出了一种基于轨道动态响应测量进行动态路谱分析的方法.该方法视火箭橇试验系统为橇轨耦合系统,以滑轨的动态响应作为火箭橇的基础激励条件,通过分析冲击响应谱获得滑轨的路谱特性.试验时选取火箭橇经过滑轨上该点时的加速度响应作为火箭橇的基础激励,得到火箭橇基础激励的加速度响应谱,再将加速度响应谱变换为位移响应谱,最后利用该点的火箭橇通过速度将位移响应谱变换为空间谱,即动态路谱.将该动态路谱作为高速火箭橇滑轨的输入进行实测分析,结果表明:谱密度值为10~10-4 mm2m,不平顺周期集中在0.01~2.50 m-1,采用动态路谱分析方法得到的滑轨不平顺特性与霍洛曼滑轨特性基本一致,可以作为高速火箭橇的随机激励条件. 

Road Spectrum Analysis of High-Speed Rocket Sled Rail Based on Shock Response Spectrum

In order to evaluate the ride comfort of the high-speed rocket sled rail, an analysis method of dynamic road spectrum based on the rail's dynamic response is presented. In this method, the rocket sled test system is regarded as a sled-rail coupling system, the rail's dynamic response is used as the excitation conditions of the rocket sled, and the road spectrum is obtained through the shock response spectrum analysis. In the rocket sled test, when the rocket sled passes a given point of the rail, the acceleration of the point on the rail is selected as the excitation of the rocket sled, and the acceleration response spectrum is established by shock response spectrum transform. Then, the acceleration response spectrum is transformed to a displacement response spectrum. Finally, using the velocity of the rocket sled on the point, the displacement response spectrum is transformed to a spatial spectrum,i.e., the dynamic road spectrum. In addition, the dynamic road spectrum as high-speed rocket sled rail input is measured and analyzed. The results show that the rail characteristics based on the dynamic road spectrum analysis are consistent with the Holloman rail characteristics; the power spectral density is between 10-10-4 mm2m and the irregularity period is concentrated between 0.01-2.50 m-1.Therefore, the dynamic road spectrum can be used as the random excitation conditions of the high-speed rocket sled.