CAT-FEA methods for tolerance analysis of flexible part assemblies: a critical overview

This paper deals with the actual need to make tolerance analysis of assemblies that cannot be considered rigid and require to model the compliant features of the parts, taken part and process variations into account. This happens with thin sheet-metal parts widely used in automotive and aeronautic fields. While the tolerance analysis of rigid assemblies is well known and documented, and supported by several commercial software, and the flexible behavior of sheet metal manufactured parts can be well studied with Finite Element Analysis (FEA), relative few works do exist about the integration of the two methodologies to carry out tolerance analysis of deformable assemblies, which combine shape variations due to the part manufacturing process with the compliant effect of the parts during the assembly phases (see positioning, clamping, fastening phases, and so on). Authors critically review the main works on this topic, highlighting the model description, the accuracy of results, the computational efficiency, and the adaptability to the existing CAD/CAT systems. Finally, a simulation will be presented integrating some interesting approaches.