Simulation of transient force and strain during thermal mechanical testing relevant to the HAZ in multi-pass welds

Abstract

The transient force and strain typically experienced in the heat affected zone of multi-pass welds were simulated using an electro-thermal mechanical testing (ETMT) machine, and the measurements were compared with numerical calculations. The thermal input data for these tests was obtained from welding experiments on 16 mm thick high strength quenched and tempered structural steel. The samples were subjected to thermal cycles under different mechanical constraints to represent realistic welding conditions. Phase transformations and high temperature elasto-plastic deformation were observed, describing time dependent material response. A comparison of experimental and numerical results indicates good agreement in strain evolution, but a deviation in the force was found during fast cooling from high temperatures due to modified material properties. Our results show that ETMT offers insight into transient force and strain evolution, which is beneficial for the validation of weld models and associated material data.