【摘要】 冲击压痕法作为近年来出现并已得到工程应用的一种新型残余应力测量技术 ,正在受到日益重视。已有试验结果表明 ,该方法的有效应用必须基于避开压痕周围的塑性区 ,利用压痕外的弹性区应变增量变化规律 ,但目前尚无定量的理论分析结果。本文采用有限单元法 ,通过数值分析研究了采用压痕法测定残余应力时压痕周围塑性区的变化规律 ,发现对于一般金属材料 ,当压痕直径为1.2mm、残余应力达到材料屈服强度时 ,从压痕中心算起的塑性区半径约为 4mm。该塑性区尺寸为设计专用压痕法测量残余应力用应变花提供了重要依据 ,从而可以保证应力测量时将应变栅布置在塑性区外 ,避免塑性区的应变扰动导致压痕法测量残余应力时的线性规律发生偏离更多还原

【Abstract】 The impact indentation method is an new stress measurement technique developed and applied recently.The experimental results have shown that the main point of applying the method is just based on the strain overlap increment in elastic region,not plastic region,apart from the indentation.But there is no any evidence from theoretic analysis.In this paper,the plastic zone around an indentation was investigated by finite element method (FEM) when the residual stress was measured with the impact indention method.It was discovered that maximum radius with 4mm will be formed around the indentation with 1.2mm surface diameter for common metal materials under the action of high value stress.Therefore,the measuring strain gage should be arranged apart from the plastic zone in order to avoid its disturbance on the linear rule while stress determination.更多还原