单边缺口拉伸试样喷丸强化残余应力及其三维应力强度因子分析

Analysis of Residual Stresses and Three Dimensional Stress Intensity Factors for Shot Peened Single-edge-notch-tension Specimens

采用有限元计算软件ABAQUS/Explicit建立40Cr钢单边缺口拉伸(SENT)试样喷丸强化的三维有限元模型,分析各喷丸参数与强化后残余应力场的关系。用三维裂纹权函数法求解了三维表面裂纹在喷丸残余应力场下的应力强度因子,并分析各喷丸参数对残余压缩应力强度因子Kres的影响。计算结果表明:当裂纹尺寸较小时,表面残余压缩应力越大,残余压缩应力强度因子绝对值-Kres越大;随着裂纹尺寸的增加,残余压应力层越深,-Kres最大值的发生位置也越深;当裂纹达到一定尺寸时,-Kres受残余压应力场深度变化规律的影响,即残余压应力场的深度越大,-Kres越大。

The shot peening process of 40Cr steel single-edge-notch-tension （SENT） specimens is simulated by finite ele- ment method using ABAQUS/Expiicit codes. The influence of shot peening parameters on the residual stress field is studied. A three-dimensional weight function method is used to calculate stress intensity factors for surface cracks in the residual stress fields induced by shot peening, and the influence of shot peening parameters on the compressive residual stress inten- sity factor, K is analyzed. It is found that when the surface crack is relatively small, Kres is mainly influenced by the sur- face compressive residual stress; the higher the surface compressive residual stress, the larger the absolute value - Kres. With the increase of crack size, the deeper the compressive residual stress field is, the deeper will the maximum - Kres takes place. When the surface crack reaches a certain dimension, -- Kres changes mainly with the depth of the compressive residual stress; the deeper the compressive residual stress field, the larger is the --Kres.