Research On The Test Method Of Characteric Parameters Of Railway Vehicle Bodies

The inertial parameters and modal parameters of the railway vehicle body directly affect the vibration characteristics of the vehicle system.Therefore,it is necessary to obtain these parameters accurately through tests.However,the huge structure of the vehicle body brings many difficults for testing and this will lead to inaccurate test results.This thesis compared the testing methods for these structural feature parameters in different fields and studied the testing methods which is suitable for railway vehicle bodies based on virtual prototype technology.The main research work is as follows:(1)By comparing the different methods to test these structural parameters in different fields,it is determined that the 6-DOF virbration test bench can be used to test these parameters of railway vehicle body with the consideration of the operability,safety and accurate of the test;(2)A virtual prototype of the 6-DOF virbration test bench was established by using SIMPACK.Firstly,the solution method of the control signal of the test bench was studied.The driving signals of the test bench was obtained by inversely calculated the target motion position of the test bench through homogeneous coordinate transformation.Through this method,the test bench was successfully controlled to reproduce random vibration signals in different directions,which verified the correctness of the control signal solution method of the test bench,and provided the basis for the subsequent control test bench to test the vehicle body;(3)The actual test process of the vehicle body inertia parameters was reproduced on the virtual prototype of the test bench.The influence on the test results which was caused by the structure of the test bench was considered emphatically.The virtual test data was processed by MATALAB programming,and the inertia parameters of the vehicle car body was obtained more accurately;(4)The rigid-flexible coupling system between the test bench and the vehicle body was established.The test method of vehicle body modal parameters by simulating the actural running position of the train on the virbration test bench was studied.The excitation method of the modal test was determined,the calculation method of the maximum loading capacity of the test bench was given,the influence of the vehicle body support stiffness on the modal test results was discussed in detail,and the feasibility of the test method was verified through virtual tests.The method of matrix perturbation is used to correct the slight influence of vehicle support stiffness on modal test,and a good correction result is obtained,which reduces the requirement in modal test.