Prediction of laser welding failure on seat mechanisms simulation

For some years, FAUREClA has chosen to industrialize LASER welding technology (Fig. 1 ) to weld it seat components, This choice is a consequence of global lightweight policy in industrial automotive world, To fully answer to this requirement Faurecia needs to join thinner parts using higher strength steels. On one seat sevenl tens of welding lines will be used to join parts with thicknesses from O.S mm to 5 mm. Conventional processes such as resistance spot we/ding or metal active gas have reached their limits where laser welding offered again high potential. The LASER process oHen higher flexibility in term of weldable materials, thichness and seams geometry. LASER is also faster than conventional process and does not need filler metal. On new structures, all weldings are done by one process instead of 2 or 3 in the past, For all those reasdns Faurecia, decided to invest in this high potential joining process. In Faurecia, several join types are used, overlap scan welding, T-joins welding, edge to edge... This study will deal only with overlap scan welding, which represents the most impo_ant part of the seat structure welding, but could be extrapolated to others, For this study, we need to distinguish mo hinds of welding rupture. First is the rupture of the joint itself called melted zone rupture. Second one is the rupture of the material at the welding faot. This rupture appears in an area called Heat Affected Zone (see Fig, 27 and represents the main welding failure mode observed during development phase.