Fatigue Life Prediction After Laser Forming

Abstract

Analysis of the laser forming process has been focused on geometry, yield strength, and microstructure change in the past. However fatigue life has been the primary concern for engineering components in many applications. For laser forming to become a practical rapid prototyping tool, research has to be done to predict fatigue life of sheet metal after laser forming. Microstructure as well as the distribution of residual stresses and strains changes during laser forming process. The current models cannot predict the fatigue life after laser forming accurately because of differences in assumptions. This work presents a model to predict fatigue life of sheet metal after laser forming. Results from microstructure integrated finite element modeling of laser forming are incorporated in the fatigue life model. Low carbon steel is used in this work to validate the model. It is shown that the proposed model can predict the fatigue life of sheet metal after laser forming with good accuracy. The predictions from the model are consistent with experimental results. Effects of laser forming conditions on fatigue life of sheet metal are under investigation.