Robust Fixture Configuration Design for Sheet Metal Assembly With Laser Welding

Fixturing plays an important role in the quality of metal fit-up for sheet metal assembly with laser welding. To reduce the sensitivity of the designed fixture configuration to location fluctuation, this paper provides a quality design of the fixture configuration for sheet metal laser welding. A generic robust design methodology, labeled the two-stage response surface methodology, is developed in the robust design model. The first stage is to find the Robust Design Space (RDS), in which robust solutions with higher degrees of insensitivity reside. Within the RDS, a second-order response surface model can be fitted by a $3k$ fractional factorial design in the second stage. Based on the resultant response model, the robust fixturing scheme and the influential design locators can be obtained by an optimization and a statistical screening techniques. The degree of metal fit-up is taken as the performance characteristic of the robust design. An example illustrates how the robust design method effectively meets the quality requirements of the fixturing design.