Investigation of effect of two-side laser shock order on small-hole specimen strengthening

Small-hole components have typical details of stress concentration so that they are easy to produce fatigue cracks under fatigue load and the usage performance and service life of critical structures are easily affected. In order to study effect of two-side laser shock processing (LSP) order on strengthening of small-hole specimens, fatigue tensile tests of TC4-DT hole components by two-side LSP simultaneously and two-side LSP successively were carried out. ABAQUS finite element software was adopted to conduct simulation study on residual stress distribution of TC4-DT hole components after different two-side LSP. The results show that the specimen fatigue gain after two-side simultaneous LSP is above 2 times than that after two-side successive LSP. Residual stress distribution of a hole component after two-side simultaneous LSP is more homogeneous. And the fatigue source deviates from the midpoint of the thickness significantly. The difference of residual stress of two LSP surfaces is large after two-side successive LSP. The simulation results have good agreement with the experiment results.