Fixture Configuration Design for Sheet Metal Assembly with Laser Welding: A Case Study

The role of assembly fixtures is gaining importance in order to meet the special requirement of metal fit-up for sheet metal assembly with laser welding. Fixture configuration methodologies based on a new proposed locating scheme have been developed. In order to demonstrate the feasibility of the proposed fixture design principles in industrial applications, an industrial case study with cross-members assembly is presented. In order to obtain a physical model with the actual tolerances, reverse engineering technologies are employed for geometric modelling of the assembled parts. For achieving modelling accuracy a CMM-based finite-element model is produced and performance characteristics of the 3D features obtained. In the case study, the assembly weld patterns are designed first, to determine the weld locations. Then the general design, the deterministic optimisation and the robust design of the fixture configuration are carried out sequentially. The results of the case study show that the proposed fixturing principles are applicable and effective.