단일 숏 충돌시 피닝잔류응력 유일해를 위한 2차원 유한요소해석 모델

Abstract

Abstract In this paper, we propose a 2D-FE model in single impact with combined physical factors to obtain a unique residual stress by shot peening. Applied physical parameters consist of elastic-plastic deformation of shot ball, material damping coefficients, strain rate, dynamic friction coefficients. As a kinematical parameter, there is impact velocity. Single impact FE model consists of 2D axisymmetric elements. The FE model with combined factors showed converged and unique distributions of surface stress, maximum compressive residual stress and deformation depth. Further, in contrast to the FE models with rigid shot and elastic deformable shot, FE model with plastic deformable shot produces residual stresses very close to experimental solutions by X-ray diffraction. We therefore validated the 2D FE model with combined peening factors and plastic deformable shot. This FE model will be a base of the 3D FE model for residual stresses by multi-impact shot peening. 1. 서 론 잔류응력은 박막제조나 표면코팅, 그리고 기계 가공 및 열처리, 숏피닝 및 레이져피닝 등에 의해 발생된다.