FAILURE ASSESSMENT OF TRANSMISSION DIODE LASER WELDED POLYPROPYLENE

Abstract

The aim of present work is to predict using finite element analysis the failure of polypropylene welded samples using the Laser Diode Transmission technique. The studied material is a commercial polypropylene (PP). The mechanical behaviour of the welded samples is modelled using elastic purely plastic law with a von Mises yield criterion. Both the thermal degradation and the heterogeneity of the weld zone were taken into account in the modelling, to approach the welding conditions and the geometry of the weld. The linear mechanic’s fracture was adopted to assess the failure of the welded samples. The assumption of the plane deformations is chosen to calculate the integral of contour of Rice “J” and to characterize the singularity of the stress field surrounding the weld zone. Good agreement is. The good agreement observed between the predicted and this experimentally obtained load failure suggests that our approach can be used as a tool for the prediction of failure of laser diode welded specimens.