Fracture Behavior of CFRP Laminate under Artificial Lightning Strike

This paper examines the fundamental fracture behavior of CFRP laminate due to lightning strikes. In order to clarify the influence of lightning parameters and specimen size variations, the comparative results of performing artificial lightning strike testing on a series of laminated composite specimens has been explored. For the artificial lightning strike testing, the high-strength/middle-modulus graphite/epoxy composite of IM600/133 is selected as a typical aerospace grade material. The damage to the CFRP laminate was assessed by using visual inspection, ultrasonic inspection, micro X-ray inspection, and sectional observation. The test results clarified that the damage mode can be categorized into three different damage mode of fiber damaged area, resin deterioration area, and internal delaminations. And the damage progress is governed by the strong electrical and thermal orthotropic properties of CFRP laminates. As a result of damage size evaluation, it is confirmed that the lightning parameters which define impulse waveform show strong relationship with certain damage modes though the specimen size and thickness variation hardly affect damage size due to lightning strike.