Manufacturing process simulation for tolerance analysis and synthesis
Résumé
The choice of a manufacturing process (machine-tools, cutting tools, part-holders, process plan) which allows
the production of parts conform to the objective in term of quality and price depends on many criteria. One of
these criteria is the respect of the functional tolerances of the part. To check this point the manufacturing
process is simulated (positioning and machining operations). The result of this simulation is a Model of
Manufactured Part (MMP). The deviations of all the surfaces of the MMP are described with regards to their
nominal position (nominal part) using a small displacement torsor. Then, for all the functional tolerances to be
verified, a virtual gauge is created and assembled with the MMP and the gap between the tolerance zone and the
toleranced surface is calculated. The verification of each tolerance is provided by a system of inequalities
representing the non-contact conditions between the toleranced surface and the tolerance zone limits. The ability
to machine a series of parts closed to the functional tolerances being verified, the ISO or non-ISO manufacturing
tolerances to define the workpiece at each set-up is determined. These tolerances are useful to follow the
conformity of the workpiece at each step of the machining process.