Research on the frequency contribution and improvement method for car body modes of high-speed train
In order to solve the difficulties of traditional sensitivity analysis by identifying prioritized improvement components in the process of enhancing low-order modal frequencies of high-speed train car bodies,a novel method for evaluating modal frequency contribution and improving car body structure was proposed. The study analyzed the relationship between the thickness of aluminum alloy body panels and the sensitivity of modal frequency. Additionally,the concept of component modal contribution was proposed,and a mathematical model describing the sensitivity and contribution of component modal frequency was derived and established. By calculating the contribution of each aluminum profile in the rolling stock body,the influence of six major components,such as the roof,sidewalls,and underframe,on the first three orders of modal frequencies was analyzed in detail. The component modal contribution reveals the extent to which each local component affects the overall structural modes,providing a global quantitative index that cannot be shown by sensitivity. The roof components have the greatest contribution on the first three body modes,followed by the sidewalls and chassis. The chassis edge beams,end walls,and traction buffer have the least contribution. The profiles at the junctions between the roof and sidewall,as well as the sidewall and chassis,have a significant effect on the body modes. To enhance the first-order droop-bend modal frequency,the thickness of the inner and outer panels can be increased while moderately reducing the thickness of the inner fascia. By applying the proposed method,we successfully screened and improved priority optimization components such as roof and joint profiles based on the modal contributions of 54 vehicle body components. As a result,the 1st-order droop-bend modal frequency improved from 9.5 Hz to 10.2 Hz while controlling the increase in vehicle body weight to less than 43 kg. This verifies the validity and high efficiency of the method and provides a clear path for optimizing the modal frequency of the vehicle body. The method is widely applicable and can be generalized to improve structural modes in other fields.
high-speed train car bodymodal contributionsensitivitymodal frequencystructural improvement
万方数据
维普
