A numerical simulation of the residual stresses in laser-peened friction stir-welded aluminum 2195 joints

Purpose - The purpose of this paper is to present an analytical framework for predicting the residual stresses that result from the laser shock peening of a friction stir-welded 2195 aluminum alloy sample, using the finite element software LS-DYNA.Design methodology approach - The pressures resulting from the laser peening are directly applied in an explicit transient analysis as forces. At the completion of the transient analysis, an implicit springback analysis is performed to determine the final residual stresses. This cycle is repeated for the appropriate number of peen applications, including the appropriate overlap of application areas. To validate the analytical framework, a comparison of residual stresses between analysis and a test specimen is made using laser-peened base material which was not friction stir-welded. Friction stir welding (FSW) causes residual stresses and material property variations. In this work, the varying material properties regions are simplified and defined as discrete, separate materials. The residual stresses resulting from the welding are introduced directly as initial conditions in the peening transient analysis and so are combined within the analysis with the residual stresses from the peening.Findings - Comparisons made between the experimental and analytical residual stresses are generally favorable.Originality value - Analysis of the laser shock peening of FSW has not been accomplished previously.