Nonrigid parts' specification and inspection methods: notions, challenges, and recent advancements

In a free state, nonrigid parts can take on different shapes compared to their design model. Such behavior of nonrigid parts introduces particular challenges to engineers during the geometric and dimensional requirements specification and inspection steps. Given that the choice of inspection method is guided by the requirement specification type, this paper presents two sections dealing, respectively, with the specification and the inspection method used for nonrigid parts. Accordingly, this paper proposes a categorization of the particular specification methods used for the geometric dimensioning and tolerancing of nonrigid parts under the American Society of Mechanical Engineers and International Organization for Standardization standards, as well as a review of the available approaches for the fixtureless inspection method of these parts. Typical applications of each specification method, as well as the advantages and drawbacks of their use, are proposed as general guidance. Finally, the current research trends into the fixtureless inspection methods of nonrigid parts are underscored.