Low velocity impact fatigue studies on hybrid composite laminates with varied material and test parameters – effect of impact energy and fibre volume fraction

Abstract

This article is devoted to study the effects of fibre volume fraction and impact energy on the impact damage tolerance of composite laminates subjected to low velocity impacts at constant strike velocities. Repeated drop tests were conducted using a drop weight impact tester. Delamination area was used as parameter for quantifying damage while the number of drops (impacts) to failure used to assess the damage tolerance limits. The delamination area was found to increase and then saturate after a certain number of drops. Impact fatigue studies showed the existence of a critical incident energy around which design of composite structures can be based. One of the interesting observations made was that for any given incident energy, the delamination area was found to be minimum at a certain fibre volume fraction of the laminate.