Influence of impact velocity and lay-up parameter on impact damage resistance of CF/PEEK laminates

Abstract

In order to use composite materials in aeronautical turbo engines, their resistance to impact damage must be understood. The carbon fiber reinforced polyether-etherketone system (CFIPEEK) is a prime candidate for composite engine components because of its high impact resistance. In this work the influence of impact velocity and stacking sequence on subperforation flat-wise impact resistance for CFIPEEK laminated composites (APC-UAS4) was evaluated under low and high velocity impact tests. The stacking sequences of the specimens were (0/+30/0/-30)s, (0/+60/0/-60)s and (0/+45/90/-45)s. A drop weight test system was used for the low velocity tests, where the velocity ranged from 1.5 to 3.1 mls. An air gun system was used for the high velocity tests, where the velocity range was between 50 and 100 mls. The projected damage area was measured with an ultrasonic C-Scan. The relation between damage area @A) and impact energy (IE) was linear, and the ratio of the DAAE quantitatively indicated the impact resistance of this system. To estimate the effect of the stacking sequence related to the DAIIE, the stacking parameter p, which indicates the difference of the inplane stiffness between the adjacent laminae, was proposed. A proportional relation between the DAAE and the stacking parameter was obtained for both low and high impact velocity levels.