Photoelastic Stamping Analysis Adds Vision to New Automotive Material Developments

This paper introduces a new technique, developed at Chrysler Corporation, for analyzing forming strains induced in sheet metal stampings. This technique, designated as the Photoelastic Stamping Analysis, employs thin plastic, photoelastic coatings to visually illuminate the overall forming strain distributions and magnitudes, on the surface of formed parts. This is accomplished by modifying an established photoelastic coating technique, whereby, photoelastic strain measurement capabilities are extended from the elastic region to cover the total range of plastic deformation. This technique was developed to assist in resolving design and manufacturing problems related to developing materials for stamped sheet metal parts. Current formability tests are described, followed by the presentation and discussion of the Photoelastic Stamping Anaylsis.