On the First Failure Energy of Glass-Fiber-Reinforced Plastic Panels Impacted at Low Velocity

• Published in: Mechanics of advanced materials and structures Vol. 18; no. 6; pp. 396 - 402
• Main Authors: Caprino, G., Lopresto, V., Durante, M., Iaccarino, P.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.09.2011
• Subjects: delamination; elastic behavior; first failure energy; impact behavior; polymer-matrix composites
• ISSN: 1537-6494; 1537-6532
• DOI: 10.1080/15376494.2010.524971

Low velocity impact tests at various energy levels were carried out on simply supported circular glass-fiber-reinforced plastic laminates made of glass fabric/epoxy prepreg. Four panel thicknesses, keeping the stacking sequence unchanged, and two tup diameters were employed, to verify the influence of these parameters on the elastic behavior and first failure conditions of the material. A four-parameter model considering the membrane effects and indentation, and explicitly accounting for the panel thickness and tup diameter, previously assessed for graphite-fiber-reinforced laminates loaded statically, was applied to predict the critical energy at first failure. The calculated values were in reasonably good agreement with their experimental counterparts, allowing the evaluation of the energies causing not only delamination initiation, but also first fibee failure. Only for the thickest laminate, the model yielded a far conservative estimate of the critical energy at first fiber failure, due to the deviation of the experimental load-displacement curve from the theoretical trend, induced by delamination.