Comparative Evaluation of Quasi-Static Indentation Behaviour of Glass Fiber Reinforced (GFRP) and Carbon Fiber Reinforced (CFRP) Laminates

Abstract

A comparative study of Quasi Static Indentation (QSI) conduct of Glass Fiber Reinforced Laminates (GFRP) and Carbon Fiber Reinforced Laminates (CFRP) of different thicknesses is made in this work. QSI tests are performed as per ASTM Standard D 7766M using custom – built Digital Flexural test equipment with dedicated fixture which provides constraint from all the four sides. A hemispherical Indentor of 12.5 mm diameter made from hardened steel is used to indent the specimens at a speed of 25 mm/minute. The damage area at different stages of QSI are assessed using ultrasonic ‘A’ scan and macroscopic inspection. The influences of thickness and type of laminate on the QSI parameters such as peak load at fracture, energy absorbed till fracture and maximum deflections are determined. It is found that the initial stiffness and the energy required for complete fracture is significantly more in case of CFRP as compared to GFRP laminate.Key words: QSI, GFRP, CFRP, Energy, Peak load, Initial Stiffness.