Simulation and Analysis of multi-station assembly processes of compliant assemblies

Controlling parts, assemblies and tools variation is an important task in the manufacturing processes, strictly related to the process quality control. In particular, predicting how parts and assemblies may vary under different assembly configurations is a strategic task, today performed with sophisticated computer simulations. Moreover, if the analyzed parts/assemblies are very flexible, for which the assumption of rigid body performance are not applicable, the statistical variation analysis may be difficult to do and results may be not accurate. For compliant assemblies, in fact, the common computer simulations made by Computer Aided Tolerancing systems are unable to predict well the real behavior of such assembly processes. The analysis is much more complex if we simulate the movement of the parts and/or subassemblies from one assembly station to the next one: some variations may be compensated while others amplified. Combining statistical variation analysis with finite element analysis is necessary to accounting such shape variability. Monte Carlo simulations are a very time-consuming solution when having to manage FEA runs, so an alternative method must be evaluated. Here, a linear approach to the simulation and analysis of multi-station compliant assembly processes is described. Its applicability to a real contest is also discussed.