Different Optimization Models for Crack-Free Laser Welding

Conventional laser beam welding of aluminum alloys often leads to hot cracking. This is caused by a complex process where thermo-mechanical and metallurgical aspects are involved; cf. 3], 2]. A possibility to prevent hot crack initiation yields the multi-beam welding technique (cf. 2]), where additional laser beams are led parallelly besides the main laser beam. There by optimal positions, sizes, and powers of the additional laser beams play an important role otherwise hot cracking can even be enhanced. In 1], 4], resp., a mechanical 1D and thermal 2D model of hot cracking was derived. It provides the basis for different formulations of constrained nonlinear programming problems to identify the optimal parameters of the additional laser beams. In the present paper a comparison between these formulations and between two different optimizers for the so far best formulation are presented. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)