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Unformatted text preview: es Functional Requirements (clearances) in operation as a starting point. With this information, an uncertainty allocation process (synthesis) is performed, yielding a set of part uncertainties at operation conditions. At the same time, computations are performed, using analytical or finite element models, to estimate the strains on each part in operation. Dimension values are also tuned, so that the corresponding chains of dimensions yield the nominal clearance, as specified by the requirements at operation conditions. The goal of the following step in the procedure is to convert geometrical data from operation conditions to assembly conditions. For that purpose, the values of the strains are being utilized to compensate the corresponding dimensions on the parts so as to reflect their original values at assembly. For instance, if loads and temperature increase the length of a part, then the corresponding strain should be subtracted from the nominal length of the part in operation, therefore providing the original dimension at assembly. Part uncertainties need not to be compensated since such compensations would be equivalent to second order variations (...
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- Spring '10
- The Land