Load Identification of Bogie Frame Based on Dynamic Stress

Abstract

Load identification using instrumented bogie frame has higher accuracy but it is complicated and costly to conduct. In some cases there is no prerequisite for utilizing the instrumented bogie frame. The method for load identification of bogie frame is presented under the condition that only the dynamic stress data and the load-stress correlation matrix are given. The correlation matrix is often ill-conditioned in this case, which can affect the precision of identification significantly. The cause of the induced error by ill-conditioned matrix and the principle of the truncated singular value method to control the error are analyzed in detail. The dynamic stress data and load-stress correlation matrix of a certain type of EMU are used to identify the loads of bogie frame by the truncated singular value method. The results are compared with the measured loads obtained by the instrumented bogie frame method. The identified loads agree well with the measured loads in terms of the amplitude, phase and equivalent value. The results show that the truncated singular value method can effectively identify the ups and downs, torsion, side roll, anti-snake, gear box load and brake load of bogie frame.