摘要
为了解决某冷凝器支架开裂故障,首先采集车架纵梁前、后两端的随机振动激励,得到激励端的时域载荷谱,并且将其转换为功率普密度曲线。然后基于单位载荷的频率响应分析得到频率应力的传递函数,以此对该冷凝器支架进行随机振动疲劳分析,分析结果表明其疲劳寿命低于工程要求值,其危险点区域和开裂位置相同。再基于集成平台对冷凝器支架的厚度进行多目标优化,优化之后冷凝器支架的寿命满足疲劳性能要求,其重量达到了最轻,优化效果良好。最后按照相应的试验规范对冷凝器支架的优化方案进行道路试验,试验结果表明冷凝器的频域加速度大幅度降低,冷凝器支架也未开裂,成功解决了该故障问题,整个系统分析方法为类似支架的设计开发提供了科学依据和理论参考。
Aiming at solving the cracking problem of a condenser bracket. Firstly, the front and rear frame longitudinal beam random vibration excitation were collected, the time domain load spectrum of the excitation end were obtained, and they were converted to power spectral density curve. Secondly, the frequency stress transfer function were obtained by frequency response analysis based on unit load, and then the condenser bracket was vibration fatigue analysised, the analysis results show that the fatigue life was lower than engineering requirement, its danger zone was same as cracking position. Thirdly, the condenser bracket thickness were multiobjective optimized based on integrated platform, its life could meet fatigue performance requirements after optimization, and its weight was reduce, so the optimization effect was good. Lastly, the condenser bracket optimization scheme was road test based on test specification, the test results show that the condenser bracket frequency domain acceleration was greatly reduced, and the condenser bracket didn't crack, so the cracking problem was successfully solved. A scientific basis and theoretical reference were provided for the similar brackets design and development by the whole system analysis method.
引文
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