FATIGUE BEHAVIOUR PREDICTION OF LASER SURFACE TREATED ALUMINIUM PLATES THROUGH SIMULATION OF THE LASER STRIPPING PROCESS

Laser techniques are currently applied in a series of engineering processes due to their technological and economic advantages. Characteristic applications are the cutting of complex shapes, drilling on curved surfaces, welding of dissimilar metals, surface treatment etc. In the present work the numerical simulation of the laser paint removal process, which aims on the understanding of the fatigue behaviour of laser surface treated plates, is presented. The application of laser radiation (carbon dioxide and excimer) is associated with significant fatigue life extension. The observed enhancement of fatigue life is attributed to the development of compressive residual stresses during the paint removal processing. To enable prediction of the fatigue behaviour of the surface treated material, a numerical model is developed for simulation of the laser paint removal process. The model is based on a nonlinear transient coupled thermal-structural analysis and accounts for the temperature dependency of the thermal and mechanical properties of the material. The model is applied in the calculation of the residual stresses of the paint removal process. The simulation results correlate well with the experimental results and enable prediction of the fatigue behaviour of the laser treated material, based on the fatigue curves of the original material. 1