Load frequency determination method for electric vehicle differential torsional impact fatigue test

Abstract

The invention discloses a load frequency determination method for a torsional impact fatigue test of an electric automobile differential, relating to the technical field of electric vehicles. The method comprises the steps of obtaining a dangerous cross section as a strain test point by analyzing the stress of a key part, converting an S-N curve into a torque-fatigue life curve through a relationbetween actually measured strain and torque, determining an amplitude range of a test load, testing and loading strain under loads with the same frequency and different amplitudes, and performing statistical analysis on strain data, wherein an analysis result shows that the strain is basically linearly changed along with the loading amplitude; and selecting m test amplitudes in the amplitude rangeof the test load, obtaining fatigue life values corresponding to the m test amplitudes according to the torque-fatigue life curve, and establishing an equation set to solve the loading frequency corresponding to each loading amplitude. According to the invention, the technical problem of how to objectively determine the test load plus carrier frequency for the torsional impact fatigue test of theelectric automobile differential is solved.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to a method for determining the load frequency of a torsional impact fatigue test on a differential of an electric vehicle. Background technique [0002] As environmental and energy issues become more and more serious, pure electric vehicles are the representative of new energy vehicles, and the research and development and testing of motors, electronic control systems, and mechanical transmission systems have become the focus of the industry. As the power source of electric vehicles, the motor has the advantages of quick response and stable control of output torque. However, due to the principle of electromagnetic induction and the weak damping characteristics of the electric vehicle drive train, after the command torque is given, the output torque of the motor will fluctuate up and down in the command torque value, which not only affects the smoothness of the torque, but...

AI Technical Summary

Problems solved by technology

At present, the standards for the torsional impact fatigue test of the electric vehicle differential are still lacking, especially the lack of objective specifications for the frequency of the test load, which is basically determined subjectively by humans, resulting in a large difference from the fatigue damage during actual driving

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