摘要
超速预加载是叶轮制造过程中的重要环节,它不仅仅是检验叶轮质量的手段,更是一种巧妙的工艺过程。通过建立叶轮的有限元模型并对超速预加载工艺过程进行模拟分析,以阐释其中的力学原理。首先对半开式叶轮进行弹塑性分析,结果表明,叶轮在经过超速预加载处理后会在高应力区产生残余应力,使得其在正常工况下的最大应力有所降低;随后利用FE-SAFE分别对半开式叶轮在启停和转速小幅波动两种工况下的疲劳寿命进行分析,通过对比有无超速预加载处理的结果得知,超速预加载处理会在很大程度上提升叶轮的疲劳寿命,甚至可以避免疲劳破坏的发生;最后,对多种荷载作用下的闭式叶轮进行了疲劳分析,结果显示超速预加载处理之后的闭式叶轮可以抵抗更大的交变气动载荷而不会出现疲劳破坏。
Over-speed preloading is one of the important parts in the process of impeller manufacturing,it is a method of checking the impeller＇s quality and a subtle strengthen treatment. To explain the mechanics principle of over-speed preloading,finite element models of the impeller are established and then we simulate the process of the over-speed preloading. Firstly,an elastic-plastic analysis is carried out on the semi-open impeller,and the results show that there will be residual stress generated in the high stress regions after preloading,which can reduce the maximal stress produced in the later normal loading. Secondly,analysis of the fatigue life of the semi-open impeller at two different conditions of the starting and stopping and the speed rotating is accomplished through FE-SAFE. By contrast with the results of processing with and without over-speed preloading,we can see that the treatment of over-speed preloading can improve the fatigue life of impeller in a great extent. Moreover,over-speed preloading can also avoid the occurrence of fatigue damage in some conditions of impeller＇s speed rotating. Finally,fatigue analysis has been done for closed impeller in a variety of different loading conditions. The results show that the impeller treated with over-speed preloading can resist larger aerodynamic load and avoid fatigue damage.
出处
《机械强度》
CAS
CSCD
北大核心
2017年第6期1423-1431,共9页
Journal of Mechanical Strength
基金
国家自然科学基金项目(11272074)
973项目(613277)资助~~
关键词
叶轮
超速预加载
残余应力
疲劳寿命
Impeller
Over-speed preloading
Residual stress
Fatigue life
