A Machining Allowance is necessary if the optimisation result is manufactured with Additive Manufacturing processes . After printing the part all functional surfaces are post processed and therefore enough material needs to be available. where functional surfaces should be postprocessed. With MSC Apex GD Machining Allowances can applied on surfaces where a specified amount of additional material will be left in place to later be removed an a precison machining process like milling.
So the optimisation actually needs to produce different outputs for different requirements of the model - once a norm geometry and once a printing geometry.Picture Norm Geometry vs MA Geometry
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The optimisation is carried out and calculated without taking the Machining Allowance into consideration. It is added after the calculation process is done but before any smoothing algorithm has run over the geometry to guarantee a design without any transition problems between these different geometries.
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