基于功率谱密度的冷凝器支架随机振动疲劳分析及其优化
|
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.
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
[1]鲍晓东,张仙妮.重型商用车尿素箱支架设计与疲劳验证[J].机械设计与制造,2017(3):212-218.
[2]赵卫艳,谷雪松,王可,等.商用车转向器支架疲劳寿命仿真分析[J].长安大学学报:自然科学版,2011,31(1):90-94.
[3]孟强,郑松林,吴振.某汽车乘客安全气囊支架的随机振动强度分析与优化设计[J].机械设计与研究,2016,32(1):155-158.
[4]吴道俊,钱立军,祝安定,等.基于疲劳寿命的车架支架结构优化[J].汽车工程,2013,35(10):863-867.
[5]梅红杰.随机振动疲劳寿命估算方法的等效研究[D].南京:南京航空航天大学,2014:30-32.
[6]汪洋.基于模态频率响应的某重型车驾驶室疲劳寿命研究[D].合肥:合肥工业大学,2017:50-52.
[7]李福强,刘守荣,毛恩荣,等.基于功率密度的玉米收获机车架疲劳分析[J].农业工程学报,2016,32(10):34-40.
[8]夏天翔,姚卫星,刘向民,等.考虑材料分散性后Miner理论在多轴两级阶梯谱下的适用性研究[J].机械工程学报,2015,51(14):38-45.
[9]李建国,石博强,刘瑞月,等.基于Hyper Mesh-EDEM-Patran耦合的铲运机铲斗强度分析[J].机械强度,2016(2):385-388.
[10]许兆庆,裴海龙.巡飞导弹纵向弹性动态特性分析[J].机械设计与研究,2016,32(2):175-177.
[11]马明,朱玉田.基于nCode DesignLife的车载扬声器盆架振动疲劳分析[J].计算机辅助工程,2016,25(4):48-54.
[12]胡勇.汽车后悬架拖曳臂台架疲劳试验失效分析及其改进[J].机械设计与研究,2018,33(4):172-176.
[13]晏红文,田红旗,梁裕国,等.基于Isight的塔架门框结构的优化设计[J].机械强度,2015,37(4):646-650.
[14]赵国伟,唐进元,张质子.ISIGHT集成CATIA和ABAQUS的制动蹄轻量化设计[J].中南大学学报:自然科学版,2016,47(7):2260-2265.
[15]朱大林,詹腾,张屹,等.多邻域结构多目标遗传算法[J].农业机械学报,2015,46(4):309-315.
[2]赵卫艳,谷雪松,王可,等.商用车转向器支架疲劳寿命仿真分析[J].长安大学学报:自然科学版,2011,31(1):90-94.
[3]孟强,郑松林,吴振.某汽车乘客安全气囊支架的随机振动强度分析与优化设计[J].机械设计与研究,2016,32(1):155-158.
[4]吴道俊,钱立军,祝安定,等.基于疲劳寿命的车架支架结构优化[J].汽车工程,2013,35(10):863-867.
[5]梅红杰.随机振动疲劳寿命估算方法的等效研究[D].南京:南京航空航天大学,2014:30-32.
[6]汪洋.基于模态频率响应的某重型车驾驶室疲劳寿命研究[D].合肥:合肥工业大学,2017:50-52.
[7]李福强,刘守荣,毛恩荣,等.基于功率密度的玉米收获机车架疲劳分析[J].农业工程学报,2016,32(10):34-40.
[8]夏天翔,姚卫星,刘向民,等.考虑材料分散性后Miner理论在多轴两级阶梯谱下的适用性研究[J].机械工程学报,2015,51(14):38-45.
[9]李建国,石博强,刘瑞月,等.基于Hyper Mesh-EDEM-Patran耦合的铲运机铲斗强度分析[J].机械强度,2016(2):385-388.
[10]许兆庆,裴海龙.巡飞导弹纵向弹性动态特性分析[J].机械设计与研究,2016,32(2):175-177.
[11]马明,朱玉田.基于nCode DesignLife的车载扬声器盆架振动疲劳分析[J].计算机辅助工程,2016,25(4):48-54.
[12]胡勇.汽车后悬架拖曳臂台架疲劳试验失效分析及其改进[J].机械设计与研究,2018,33(4):172-176.
[13]晏红文,田红旗,梁裕国,等.基于Isight的塔架门框结构的优化设计[J].机械强度,2015,37(4):646-650.
[14]赵国伟,唐进元,张质子.ISIGHT集成CATIA和ABAQUS的制动蹄轻量化设计[J].中南大学学报:自然科学版,2016,47(7):2260-2265.
[15]朱大林,詹腾,张屹,等.多邻域结构多目标遗传算法[J].农业机械学报,2015,46(4):309-315.