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The definitions and evaluation methods used to determine dent resistance for automotive closure panels are reviewed. Although dent resistance is required under both static and dynamic loading conditions, dynamic dent resistance is emphasized because the basic definitions and methods for evaluating dynamic denting are still not well established. In order to design automotive body panels to resist denting, a fundamental understanding of the interaction between the evaluation method and the material's, mechanical, and panel's geometric parameters is required. Currently there is no standard for indenter type, speed, or indenter material to be utilized or on the basic definition of “acceptable” dent resistance. The interpretation of results is dependent on these parameters. Predictive methodologies using the finite element method are reviewed. Technical challenges in developing a quantitative measure of dent resistance are highlighted.

Classically, structural component fatigue design is based on testing and empirical models. First a series of average stress-life curves are generated from fatigue tests. Constant life diagrams are then developed accounting for mean stress effect, casting quality, surface finish, volume and other factors. Component design is then based on keeping the effective alternating stress below the diagram limit stress. While this procedure has worked well to design many components, it is based on extensive fatigue testing and empirical stress reduction factors. Thus, material and process improvements and computerization of the design process are difficult to incorporate into this test/empirical based design methodology. Fracture mechanics and damage tolerant design methodologies are used in aerospace for fatigue design. These methods predict well the fatigue life for surface scratches (rogue inspectable flaws) of about 0.25-1.27 mm in size.