7 - Damage analysis of glass fiber reinforced composites

Abstract

This chapter presents an experimental investigation using high-velocity impact and low-velocity impact testing to detect and quantify impact damage for glass fiber–reinforced polymer (GFRP) type C-glass/Epoxy 600 g/m2 and type E-glass/Epoxy 800 g/m2 plate. GFRP type C-glass/Epoxy 600 g/m2 and type E-glass/Epoxy 800 g/m2 plates were tested using a single-stage gas gun and drop weight tester. For high-velocity impact, this research investigated the effect of specimen thickness, the type of projectiles, and the impact velocity, whereas for low-velocity impact, this research investigated the effects of specimen thickness based on the number of plies, and impact energy on the failure modes of GFRP type C-glass/Epoxy 600 g/m2 and type E-glass/Epoxy 800 g/m2 using nondestructive testing. The experimental results of the high-velocity impact test showed that both types of GFRP exhibited damage in terms of fiber cracking and fiber pull out, after being tested with four different gas gun pressures. For low-velocity impact tests, the results showed that both types of GFRP exhibited fiber crack and matrix crack. Most of the impacted specimens showed that GFRP type E-glass/Epoxy 800 g/m2 experienced a smaller damage area compared to type C-glass/Epoxy 600 g/m2. From the tests, the effect of the shape of the projectile, the target thickness, the gas gun pressure, and the impact energy on the performance of GFRP were determined. It can be concluded that GFRP type E-glass/Epoxy 800 g/m2 is stronger than GFRP type C-glass/Epoxy 600 g/m2 since it has more fiber volume as it is higher in density and has good mechanical properties. Therefore, GFRP type E-glass/Epoxy 800 g/m2 is recommended to be used in aircraft structure applications.