高频振动时效的机理与实验研究

针对目前振动时效的研究仅局限于低频激振的现状,研究了高频激振条件下材料内部残余应力的变化规律.采用微观动力学理论,将构件内部材料颗粒间的关系视为多自由度有阻尼振动系统,分析了构件在发生高频共振时残余应力消除的过程；通过低阶模态振型和高阶模态振型的对比分析,研究了高频振动时效在应力均化方面的作用.通过实验验证高频振动时效的可行性,并对比了不同频率激振条件下残余应力的消除和均化结果.结果表明,高频振动时效在消除残余应力及振后构件整体应力均化方面具有较好的效果.

Mechanism and experimental research on high frequency vibratory stress relief

Considering that research on vibratory stress relief (VSR) is limited in the low frequency ranges at present, the changing pattern of residual stress in the material under the condition of high-frequency-exciting was studied. Using the microcosmic dynamics theory, the relationship among particles inside the structural part was considered as a multiple-degree-of-freedom damping system, and the eliminating course of residual stress was analyzed when the part suffered from high-frequency resonance. Comparing the mode of the specimen at the higher frequency with the mode at the lower frequency, the effect of stress homogenization at the higher-frequency-exciting was presented. The feasibility of high frequency VSR was studied by the means of experimental methods, and the results of relieving and homogenizing residual stress were given under various exciting frequencies. The final results showed that high frequency VSR had good effects in relieving and homogenizing residual stress．