残余应力和粗糙度对叶片振动疲劳性能的影响

为了研究叶片表面完整性对其振动疲劳性能的影响,本文模拟分析了某型高温合金叶片在振动疲劳实验过程中的动力学应力响应,获得叶片共振时应力幅值随时间的变化规律,分析了残余应力和粗糙度对叶片振动疲劳寿命和疲劳极限的影响规律.结果表明:叶片共振过程中的应力响应幅值先增大后减小呈周期性变化,属于"拍"现象,满足关系σ=1 046sin(242.83t)sin(5 828t);叶片的振动疲劳极限和疲劳寿命均随残余应力和粗糙度的增大而减小,振动疲劳极限和残余应力之间的关系满足σfat=510.9-0.31-70.93σrest;而疲劳极限和粗糙度之间的关系则满足σfat=9.67R2roughness-70.93Rroughness+713.23.

Influence of residual stress and roughness on the vibration fatigue of blade

To study the influence of surface integrity on the vibration fatigue properties of superalloy blade, the dynamic analysis of certain super?alloy blade during the experiment of vibration fatigue was performed by using the finite element method. The stress distribution during the vibration was obtained. The influences of residual stress and roughness on the vibration fatigue properties of blade were investigated. The results show that the stress amplitude in the vibration process increases at first and then decreases. There is a beat vibration phenomenon that the stress amplitude changes periodically during the blade resonance vibration. The limited fatigue strength of blade decreases with increasing residual stress and roughness. The relationship between the limited fatigue strength and residual stress is σfat=510.9-0.31 -70.93σrest, and the relationship between the limited fatigue strength and roughness is σfat=9.67R2roughness-70.93 Rroughness+713.23.