| DYNAMIC FAILURE CHARACTERIZATION OF LASER WELDS UNDER COMBINED LOADING CONDITIONS |
| J. HA1, H. HUH2 |
1POSCO
2KAIST |
|
|
|
|
|
| ABSTRACT |
|
This paper proposes a dynamic failure criterion for laser welds to describe the strain-rate dependent failure behavior of laser welds in the crash analysis of an auto-body. The failure criterion has been developed from experiments with nine different conditions of combined normal and shear loading including the normal loading and the pure shear loading. The experiments were carried out with a high speed material testing machine at intermediate strain rates ranging from quasi-static to 100 s-1. The dynamic failure tests were examined with four cases of the 25 mm stitch-type laser weld of CR340 1.2t, the 20 mm stitch-type laser weld of CR340 1.2t, the 25 mm stitch-type laser weld of SPCC 1.0t and the O-type laser weld with the 8 mm diameter of CR340 1.2t in order to evaluate the influence of the strain rate on the failure loads with respect to the base metal and the bead geometry. Based on the experimental data, a novel failure criterion was proposed for the description of the failure behavior of laser welds on the basis of the quasi-static failure criterion. The failure criteria are divided into two regions: the base metal failure criterion is expressed as a |
| Key Words:
Laser welding, Dynamic failure load, Combined normal and shear load, Intermediate strain rate, Dynamic failure criterion |
|
|
|
Preview
Full text via DOI
Download Citation 
Print 
