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Unformatted text preview: ree domains and therefore an effective geometric covariance model should be capable of quantifying variation from all three domains. Often short wavelength variation also has small amplitude and need not be accounted for, but the amplitude that can be neglected varies with application and should be decided by the engineer. Several covariance models have been proposed, each with different modeling capabilities. Promising models are presented in [Bihlmaier, 1999] and [Tonks and Chase, 2004]. These models require two sets of inputs, the variance of the misalignment at each closure point and descriptors that define typical surface variation caused by the manufacturing process. The methods are summarized below. 3.1. Frequency Spectrum Model The geometric covariance model of [Bihlmaier, 1999] uses the frequency spectrum to model the surface variation. In the frequency spectrum model, the average autospectrum of the mating part surfaces, found by multiplying the frequency spectrum by its complex conjugate, describes the surface variation. To find the geometric covariance from t...
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This note was uploaded on 08/03/2010 for the course DD 1234 taught by Professor Zczxc during the Spring '10 term at Magnolia Bible.
- Spring '10
- The Land