Finite Element Simulation of the Laser Shock Peening Process on 304L Stainless Steel

TL;DR

This paper uses computer simulations to study how laser shock peening affects the stress and deformation in stainless steel, helping optimize the process for practical applications.

Contribution

The study introduces a novel simulation strategy using a triangular pulse model and dual-overlap analysis for optimizing LSP parameters in stainless steel.

Findings

Higher laser spot overlap and power density increase compressive residual stress and surface deformation.

Two distinct behavioral outcomes were observed: deep compressive stress with minimal deformation or a transition to tensile stress followed by significant deformation.

Simulation results align well with existing experimental data from the literature.

Abstract

This study investigates the effects of Laser Shock Peening (LSP) on residual stress distribution and surface deformation using a Finite Element Method (FEM) model. LSP is a surface treatment process that generates compressive residual stress by applying high-energy laser pulses over nanosecond timescales. The study aims to analyze the impact of key parameters, specifically laser spot overlap rate and power density, on the induced residual stress and surface deformation. A Design of Experiment (DOE) approach was used to systematically vary these parameters. These simulations were performed using the ANSYS Explicit Dynamics FEM with a Johnson–Cook material model to capture the nonlinear constitutive behavior. The research analyzes the distribution of residual stress and surface deformation caused by LSP. Increasing laser spot overlap and power density leads to higher compressive residual stress and surface deformation, revealing two distinct behavioral outcomes: either deep compressive stress with minimal deformation or a transition from compressive to tensile stress followed by significant surface deformation and a subsequent return to compressive stress. The results demonstrate strong agreement with existing experimental data presented in the literature. This study contributes novel insights into the interaction between LSP parameters and their effects on material properties, with implications for understanding LSP techniques in practical applications. The triangular pulse model and dual-overlap analysis offer a novel simulation strategy for optimizing LSP parameters in stainless steel.

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