An adaptive tolerancing algorithm for freeform profiles

Manufacturing of freeform surfaces demands the development of tolerances based on the functionality of parts. Functionally critical portions of a surface can usually be described using the curvature of designed products. A uniform tolerance zone along the nominal freeform profile may not fulfill the functionality of the designed part, i.e. it allows the curvature to increase indefinitely inside the tolerance zone. This will affect greatly in the aerospace, automotive and other high value products. An adaptive tolerancing method based on the local curvature of a profile is presented to define smaller tolerance bands to reject non-functional products.