| Analysis of the Effects of Laser Shock Peening under Initial Tensile Residual Stress Using Numerical Analysis Method |
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Juhee Kim, Jongwoo Lee, Samhyeun Yoo |
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Department of Mechanical and System Engineering, Korea Military Academy |
| 수치해석기법을 이용한 초기 인장잔류응력에 대한 레이저 충격 피닝 효과 분석 |
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김주희, 이종우, 유삼현 |
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육군사관학교 기계시스템공학과 |
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| Abstract |
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In this paper, the effects of parameters related to the residual stress induced due to laser shock peening process to determine mitigation of the initial tensile residual stresses are discussed, such as the maximum pressure, pressure pulse duration, laser spot size and number of laser shots. In order to estimate the influence of the initial tensile residual stresses, which is generated by welding in 35CD4 50HRC steel alloy, the initial condition option was employed in the finite element code. It is found that $2{ imes}HEL$ maximum pressure and a certain range of the pressure pulse duration time can produce maximum mitigation effects near the surface and depth, regardless of the magnitudes of tensile residual stess. But plastically affected depth increase with increasing maximum pressure and pressure pulse duration time. For the laser spot size, maximum compressive residual stresses have almost constant values. But LSP is more effective with increasing the magnitudes of tensile residual stress. For the multiple LSP, magnitudes of compressive residual stresses and plastically affected depths are found to increase with increasing number of laser shots, but the effect is less pronounced for more laser shots. And to conclude, even though the initial tensile residual stresses such as weld residual stress field are existed, LSP is enough to make the surface and depth reinforcement effects. |
| Key Words:
Laser Shock Peening, Residual Stress, Initial Tensile Residual Stress, Dynamic Yield Stress |
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