Numerical simulation of residual stresses fields of DD6 blade during laser shock processing

Abstract

The object of this paper was to address the effect of laser shock processing (LSP) with single and multiple impacts on the residual stresses of aeroengine blades manufactured by a type of thick DD6 alloy of [001] orientation at 980°C. The finite element method (FEM) model of the DD6 blade was established during LSP with round laser spot, and LS-DYNA and ANSYS are employed to simulate the residual stresses fields of the DD6 blade by numerical computation. The first four modal shapes of the DD6 blade of [001] orientation at 980°C were given. Moreover, the validity of the model was verified by numerical computation and LSP experiments. As a result, the distribution rules of the compressive residual stress with different impacts multiplicity were described on the basis of discussing the measurement method of peak pressure. Results showed that the impacts number corresponding to the state of uniform stress was not the same as that related to the maximum compressive residual stress which might occur at lower number of shots. For the DD6 blade of [001] orientation at 980°C, the best compressive residual stress could be achieved by three impacts.