Optimization Design of Metro Vehicle Air Compressor Frame Structure Based on Adaptive Response Surface Method

Objective A finite element model of metro vehicle air compressor frame is established and verified through modal testing and vibration testing. It is found that the vertical bending modal frequency of the dryer frame coincides with motor harmonic frequency and the vibration isolation rate is relatively low. Under the premise of meeting modal frequency and vibration isolation rate requirements, a structural optimization design of air compressor frame is carried out by integrating finite element method and optimization techniques. Method Taking the thickness of the air compressor frame as the optimization variable, DOE (design of experiment) is firstly carried out to obtain different samples of air compressor frame, then an approximate model of air compressor frame is established using the Moving Least Squares method. Based on this approximate model, with vertical first-order bending modal frequency of the frame, vertical bending modal frequency of dryer frame and vibration isolation rate as optimization objectives, an optimization design is performed using the adaptive response surface method to obtain the optimal scheme of frame parameters. Result & Conclusion Results show that, compared to before optimization, the vertical first-order bending and the dryer frame vertical bending modal frequencies after optimization are both more than 3.0 Hz different from the rail excitation frequency (typically 15.0 Hz), motor rotation fundamental frequency (24.5 Hz), and harmonics; reaching the optimal avoidance of resonance conditions, and the vibration isolation rate can be increased by 20% to 25%, while the total mass only increases by 6%.