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Unformatted text preview: other words, there is no biunivocal relation in manufacturing reality between the nominal state and evolution of a system. On a mathematical level, this stems from a ∂f j possible change in rank of the Jacobian in the neighbourhood of the nominal ∂x i point. The "nominal value" and, therefore, this Jacobian do not have any precise meaning for an instance made of the object. This is the normal case for mechanical parts where the relative arrangements of points, straight lines and planes are specific (for example, in a combustion engine, the cylinder axis intersects the crankshaft axis at right angles). When a designer has spent days or even weeks constructing a complex object using CAD, he cannot devote the same time to exploring the dimension variations of the same object. In an endeavour to meet this need for manufacturing security at the design stage, the normal differential parametric approach is completely abandoned in this study in order to adopt the concept of perturbation of the initial state. It is a method of investigation of the final real form of a geometric object w...
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- Spring '10
- The Land