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Unformatted text preview: d geometrical variations, they are generally independent. In other words, every unspecified variation will participate to a global uncertainty zone which will quite simply be the sum of all contributors for a given surface. 2.2. Design driven uncertainties They are the only member of the user specified class of uncertainties, as described in the preceding section. They are labelled as “Required” in figure 1 because they represent the designer’s expectations in terms of part and assembly precision. For this reason, they can be considered as requirements against which the part must be checked. Practically speaking, these requirements are defined at two levels; assembly and part level. At the assembly level, clearances and fit are specified. In the Jacobian-torsor model, fits are modelled as kinematic pairs, i.e. six component torsors expressing the Geometrical Variations Management 79 amount of play or interference between two cylindrical features on different parts. The expression of fits requirements by the designer follows a standard classification relating the amount of...
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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