Abstract
Fatigue life extension of materials and structures have great impact on any engineering field, and then have been extensively researched up to the present.
Among several life extension techniques for metals and its structures, the laser peening (LP) with nano-second laser and/or femto-second laser have been highlighted, since the both of the laser peening techniques can generate deep compressive stress and material hardening fields. However, the difference between these processes and the optimum condition on the fatigue life extension are not well understood since their are conducted under extremely high strain-rate conditions.
In this work, the effects of laser peening processes incorporating both nano-second laser and femto-second laser on the predicted mechanical properties are studied by using a FEM models created with ABAQUS Dynamic schime. A Johnson-Cook material model considering temperature and strain-rate effects is adopted in the analysis, and a mechanism of residual stress, material haedening and deformation generation in the models and difference of the predicted results between both LP processes is discussed in detail.
