Covariance Modeling Method for Use in Compliant Assembly Tolerance Analysis

In assemblies involving compliant parts, springback and residual stress are caused when geometric variation in the assembly requires the parts be deformed to allow for assembly. A method is needed to predict the deformation due to the geometric variations. Researchers in the areas of Statistical Tolerance Analysis and Stochastic Finite Element Analysis have developed methods to account for statistical variation of parameters in a finite element model. A new statistical method uses an orthogonal polynomial-based covariance model to account for surface variation of the compliant parts over a wide range of wavelengths. The method has been demonstrated to match the accuracy of Monte Carlo simulation with a single calculation, and accurately model covariance data taken from real parts.Copyright © 2004 by ASME