Eur. Phys. J. Plus (2022) 137: 461
https://doi.org/10.1140/epjp/s13360-022-02638-2

Regular Article

Numerical analysis on residual stress hole generation in laser shock peening

Department of Mechanical Engineering, Indian Institute of Technology Patna, Patna, Bihar, India

^b sspanda@iitp.ac.in

Received: 11 September 2021
Accepted: 23 March 2022
Published online: 13 April 2022

Abstract

Laser shock peening (LSP) is a surface treatment process in which compressive residual stress is induced on the material. At higher peak pressure (around 2.5 times of Hugoniot Elastic Limit, HEL) the reverse plastic deformation due to convergence of release waves at the center results in the formation of a residual stress hole. Finite element simulations are carried out to observe the effect of the spatial distribution of pressure pulses (Flat loading, Spherical loading, Gaussian loading, Modified Gaussian loading, and Top Hat loading) on the residual stress distribution around the region of laser shock. Axis symmetric model is used to observe the residual stress distribution for different peak pressures and different impact radii. The authors have studied the residual stress distribution field within the semi-infinite domain with attention on the near-surface and the depth near the center region. It is observed that the distribution of residual stress along the depth is highly uneven near the surface except for the Modified Gaussian spatial distribution shock pressure pulse. It is also observed that residual stress holes can be minimized by increasing the impact radius or reducing peak pressure. The model is validated by comparing the simulation results with the experimental results. Finally, the nature of attenuation of the longitudinal wave for the different spatial distribution of shock pressures is compared.