【摘要】 残余应力的存在直接影响材料的力学性能,在压痕法中影响其压痕形状大小、压入载荷—位移曲线和隆起量,因此通过比较压痕形状大小、压入载荷—位移曲线和隆起量的大小,可以推断出构件内部残余应力,再通过有限元研究不同程度的残余应力对压痕形状、压入载荷—位移曲线和隆起量的影响。研究结果表明,残余压应力使压痕尺寸变小,残余拉应力使压痕尺寸变大,不同性质和大小分布的残余应力使压痕形状为椭圆形,压入载荷—位移曲线斜率和隆起量高度随着残余压应力的增加而增加,随着拉应力的减小而减小,当构件内部存在一定程度的残余拉应力时,随着压入载荷的继续增加出现负隆起量(沉降量),沉降量的大小与压入载荷的大小和残余拉应力的程度有关。更多还原

【Abstract】 The mechanical property of metal materials is strongly affected by their residual stress.Also the indentation size,indentation load-depth curve and the development of pile-up with a rigid sphere are sensitive to the residual stress during the indentation process.So the residual stress could be deduced by comparing to the indentation size and height of the pile-up around the indentation.Therefore,a wide range of materials with different residual stress were described by the finite element method to study the indentation size, indentation load-depth curve,development of pile-up induced by residual stress.Results show that the indentation size decreases with the compression residual stress and increases with the tensile residual stress.The profile of the indentation could be oval-shaped due to the distribution of tensile residual stress and compression residual stress.And the slope of load-depth curve,the plastic pile-up height enlarge with increasing of the compression residual stress under load,decrease with decreasing of the tensile residual stress.It is also shown that the sink-in evolves and increases gradually as continues increasing load induced by the tensile residual stress,the amount of sink-in could be related to the tensile residual stress and the magnitude of load.更多还原