Low energy impact indentation of a modified polyethylene terephtalate by instrumented falling weight

• Published in: Journal of applied polymer science Vol. 127; no. 4; pp. 2983 - 2989
• Main Authors: Martínez, A. B., Arencón, D., Navas, J., Velasco, J. I.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.02.2013; Wiley; Wiley Subscription Services, Inc
• Subjects: Applied sciences; Exact sciences and technology; impact resistance; indentation; Materials science; Mechanical properties; modeling; Organic polymers; Physicochemistry of polymers; polyesters; Polymers; Properties and characterization; Experimental test; Mechanical properties; Terephthalate copolymer; Experimental study; Indentation; Modeling; polyesters; Young modulus; Ester copolymer; impact resistance; Impact strength; Viscoplasticity; Olefin polymer; Numerical simulation; Measurement method; Dynamic model; Ethylene terephthalate copolymer; Rheological properties
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.37969

Investigation of the flexed plate impact of polymers requires the study of the local plate reaction during the contact between the hemispherical tip and the specimen. The current work investigates the low energy impact indentation with a hemispherical indenter applied to a polymer sheet with a ductile behavior. The samples were freely supported on a very rigid steel plate and transversely collided by the instrumented dart. The restitution coefficients are calculated, and a lumped mass‐spring model based on the Hertz law, which agrees with the experimental contact forces, restitution coefficients, indenter depth of penetration and permanent deformations is developed. This is an indirect method to estimate the Young's modulus at these relatively high strain rates. The influence of the geometrical parameters of the test such as target thickness, drop mass, indenter diameter, along with impact velocity are analyzed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013