基于振动时效的异质构件残余应力均匀化方法

针对异质构件在装配过程中不可避免地产生非均匀化残余应力,且残余应力随着时间变化而不断减小,从而产生应力松弛的非均匀化,将影响构件的长期稳定性这一现象,同时针对该异质构件不适合用热时效方法处理的问题,利用有限元仿真方法首先仿真异质构件残余应力的分布,然后研究异质构件残余应力在自然时效下的变化规律,最后通过模态分析得到激振频率、谐响应分析得到激振幅值,通过瞬态动力仿真分析研究异质构件残余应力在振动时效下的变化规律.仿真结果表明:在自然时效下,残余应力需要经过1 a左右的时间才能基本达到稳定.在振动时效下,初始的几个周期就可以使得残余应力达到稳定.因此,通过结果对比分析认为,基于塑性变形理论的振动时效是一种快速使得残余应力均匀化的有效方法.

Title homogenizing residual stress of heterogeneous component based on vibration stress relief

The heterogeneous component inevitably produced non-homogenization residual stress during the assembly process. As time goes on, the residual stress decreased continuously and consequently resulted in non-homogenization stress relaxation. This phenomenon affected the long-term stability of the component. Meanwhile, the heterogeneous component was unsuited to be processed by thermal stress relief. For this phenomenon, finite element simulation was used. First, the heterogeneous component residual stress distribution was simulation. Second, the change of heterogeneous component residual stress was to study under natural stress relief. Final, the vibration frequency and amplitude were given through the modal and the harmonic response analysis, and the change of heterogeneous component residual stress under vibration stress relief was researched through the transient dynamic analysis. Simulation results show that residual stress achieves stable after one year under natural stress relief. While residual stress achieves stable in the initial few cycle under vibration stress relief. So comparatively analyzing the simulation results, it is shown that vibration stress relief based on plastic deformation theory is a fast effective to residual stress homogenization.