レーザーピーニングにおける圧縮残留応力分布の解析的予測手法

抄録

Laser peening (LP) is one of several surface modification techniques which can provide compressive residual stress to a metal surface and enhance the fatigue strength. It is applied to strengthen a turbine blade of an aircraft engine and repair a core shroud in a nuclear power plant. In general, the effect of LP is evaluated by measuring the compressive residual stress in a point on the treated area. However, it is required to consider the uniformity of the compressive residual stress distribution on the top surface, suppressing generation of fatigue cracks. Furthermore, prediction of a compressive residual stress distribution is also important to optimize laser process parameters. In this paper, we propose and demonstrate a prediction method of the residual stress distribution by using laser intensity distribution and material properties. The effectiveness of the proposed method is verified by comparison of predicted and measured distributions.