Anales de Ingenieria grafica

Predicting the final shape variation of single and multi-station assemblies of compliant parts is a strategic topic especially in automotive and aeronautic industries for the wide-spread presence of sheetmetal assembly processes. The high flexibility of compliant parts causes wide final shape variations during the assembly process. Therefore, it is strategic to analyze different assembly configurations at the beginning of the design phase. Starting from the recent methodology proposed by the same authors in a previous paper to do tolerance/variation analysis of compliant assemblies in single- and multi-station configurations, the developed MATLAB-based tool, called SVA-FEA (Statistical Variation Analysis & Finite Element Analysis), is here briefly illustrated. SVA-FEA allows to pre-process FE models, imported from MSC.Patran® or HyperMesh®, defining input deviations and output variables, and including contacts between parts. Then, the results obtained with a linearization process by the MSC.Nastran® solver can be post-processed to evaluate the statistical variations - in term of mean and standard deviations - of all the points of interest. The paper presents the comparative study of tolerance/variation analysis, performed on an single-station assembly of two sheet-metal parts, between SVA-FEA and a commercial CAT system (TAA® module of CATIA® CAD system). The main differences between the two analysis tools are finally outlined