Strain rate sensitivity analysis of spot-weld heat affected materials.

Abstract : The thermo-mechanical history in each HAZ is analysed by FE simulation of the welding process. The micro-structure of each HAZ material is then replicated on tensile sample using a Gleeble thermo-mechanical simulator. The micro-structure of the simulated HAZ materials was compared to the micro-structure of the HAZ materials in a spot weld to validate the procedure. Uni-axial tensile specimens are then tested at different displacement rates. The behaviour of the base metal and the HAZ materials are strain-rate dependents but the fracture strain is not strain rate sensitive for the HAZ materials.