某轻卡制动阀支架失效分析及其优化设计

Failure analysis and optimization design of a light truck brake valve bracket

针对某轻卡制动阀支架失效问题,首先采集车架横梁两端的搓板路激励载荷对该制动阀支架进行模态频响计算,分析结果表明该制动阀支架的最大应力大于材料许用值,其最大应力位置与失效位置一致;然后基于功率谱载荷对其进行随机振动疲劳分析,分析结果表明该制动阀支架的疲劳寿命不满足疲劳性能要求,其与振动强度分析薄弱位置和失效位置相吻合;再通过集成优化平台对制动阀支架进行结构优化,优化之后制动阀支架的最大应力值和疲劳寿命值均符合性能要求值,其疲劳、强度性能显著提升,支架总重量也降低了,达到了轻量化的要求;最后对制动阀支架的优化方案进行道路可靠性验证,试验结果表明该制动阀支架的振动加速度明显减小,并且没有发生失效,科学地解决了该制动阀支架的失效问题。

Aiming at solving the failure problem of a brake valve bracket.Firstly,the brake valve bracket was modal frequency response analyzed based on the wash board excitation load of frame crossbeam ends,the analysis results show that the maximum stress exceeded the material allowable value,the maximum stress position was consistent with the failure position.Secondly,the random vibration fatigue was analyzed based on power spectrum load,the analysis results show that the fatigue life of the brake valve bracket didn’t meet the fatigue performance requirements,and it was consistent with the strength analysis weak region and actual failure position.Thirdly,the brake valve bracket was optimal designed by adopting integrated optimization platform,the brake valve bracket maximum stress value and fatigue life value met the performance requirements after optimization,significantly improved the fatigue and strength performance,the brackets total weight was also been reduced,it met the light weight requirement.Lastly,the optimization scheme of brake valve bracket was certificated by vehicle road test,the test results show that the brake valve bracket vibration acceleration was obviously decreased,and the failure was avoided,so the failure problem was effectively solved.