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Unformatted text preview: ing the mean and standard deviation of the springback and stress in each assembled compliant part. 2.1. Calculating the Total Misalignment The total misalignment in the assembly is due to dimensional variations from each part, as well as fixture and tooling error. To account for the sources of dimensional variation, all parts are considered rigid and statistical tolerance analysis (STA) is used to find the mean and variance of the misalignment for each set of mating parts. Many STA methods exist and are summarized in [Chase and Parkinson, 1991]. An additional STA method is presented in [Shen et al., 2004]. A description of this process using a vectorized STA method is found in [Mortensen, 2002]. Predicting Deformation of Compliant Assemblies 323 2.2. Calculating the Misalignment Covariance STA gives the mean and variance of the misalignment between each set of mating parts, but to solve for the springback and stress in the compliant parts, the covariance of the misalignment at the closure points (rivet/spot weld locations) is needed as is the portion of the total misalignment absorb...
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- Spring '10
- The Land