滚动转子式压缩机下外罩疲劳分析及优化设计

摘要

对某型压缩机下外罩进行脉冲试验,发现其未达到使用寿命即出现裂纹,对其失效机制进行分析,认为是应力集中导致的高周疲劳断裂.为了能够准确预测下外罩的疲劳寿命和防止问题再现,利用Solid-works Simulation软件进行下外罩静力学分析,并基于名义应力法和Miner线性累计损伤理论,对下外罩进行疲劳分析,得到下外罩的疲劳寿命,其分析结果与试验结果相吻合.对下外罩结构进行优化设计,优化后安全系数为1.025,疲劳寿命次数达到10万次以上,并进行相应试验验证,结果表明,优化结构符合设计要求.%Pulse test is carried out on the lower cover of one compressor,cracks are found before the service life is arrived.The failure mechanism is analyzed,and it is consid-ered that it is the high cycle fatigue fracture caused by stress concentration.In order to forecast the fatigue life of lower cover and prevent of problem representation,the statics analysis is conducted on the lower cover using the Solidworks Simulation software,and the fatigue life of lower cover is analyzed based on the nominal stress method and Miner Linear cumulative damage theory,so as to get the fatigue life of lower cover.The analyti-cal results are consistent with the experimental results.After optimal design of the lower cover structure,the safety factor is 1.025 and the fatigue life is greater than 100 thousand times,and corresponding tests and verification are carried out.The results show that the optimized structure meets the requirements of design.