TY  - JOUR
A1  - Reisgen, Uwe
A1  - Schleser, Markus
A1  - Mokrov, Oleg
A1  - Ahmed, Essam
T1  - Uni- and bi-axial deformation behavior of laser welded advanced high strength steel sheets
JF  - Journal of materials processing technology
N2  - Bead-on-plate butt joints of 2.5 mm hot rolled DP600/DP600 and 1.2 mm cold rolled TRIP700/TRIP700 steel sheets were performed using 6 kW CO2 laser beam welding. The welding speed ranged from 1.5 to 3.0 and from 2.1 to 3.9 m/min in DP/DP and TRIP/TRIP steel weldments respectively. A top surface helium gas was used as a shielding gas at a flow rate of 20 l/min. Metallographic examinations and transverse tensile testing (DIN EN 895: 1995) were carried out to characterize the weldments. The formability of base metals and weldments were investigated by standard Erichsen test (DIN EN ISO 20482). It was found that the uniaxial plastic behavior of both DP600 and TRIP700 base metals was in agreement with Swift and modified Mecking–Kocks models respectively. In a perpendicular tensile test to the weld line, all specimens were fractured at the base metal however the strengths were somewhat higher than those of base metal. There was a significant reduction in formability caused by welding of both DP/DP and TRIP/TRIP steel weldments and the formability has been improved with the increase of the welding speed.
Y1  - 2010
U6  - https://doi.org/http10.1016/j.jmatprotec.2010.08.003
SN  - 0924-0136
VL  - 210
IS  - 15
SP  - 2188
EP  - 2196
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Haselgruber, Nikolaus
A1  - Mautner, Karin
A1  - Thiele, Jan
T1  - Usage Space Analysis for Reliability Testing
JF  - Quality and Reliability Engineering International
N2  - During the development process of a complex technical product, one widely used and important technique is accelerated testing where the applied stress on a component is chosen to exceed the reference stress, i.e. the stress encountered in field operation, in order to reduce the time to failure. For that, the reference stress has to be known. Since a complex technical product may fail regarding numerous failure modes, stress in general is highly dimensional rather than scalar. In addition, customers use their products individually, i.e. field operation should be described by a distribution rather than by one scalar stress value. In this paper, a way to span the customer usage space is shown. It allows the identification of worst case reference stress profiles in significantly reduced dimensions with minimal loss of information. The application example shows that even for a complex product like a combustion engine, stress information can be compressed significantly. With low measurement effort it turned out that only three reference stress cycles were sufficient to cover a broad range of customer stress variety.
Y1  - 2010
U6  - https://doi.org/10.1002/qre.1155
SN  - 1099-1638
N1  - Special Issue: Business and Industrial Statistics: Developments and Industrial Practices in Quality and Reliability
VL  - 26
IS  - 8
SP  - 877
EP  - 885
PB  - Wiley
CY  - New York
ER  -