Influence of a fiberglass layer on the lightning strike damage response of CFRP laminates in the dry and hygrothermal environments
Abstract : This paper experimentally investigates the lightning strike response of a fiberglass/carbon woven hybrid laminate ([(0/90)g(45/02/-452/902)c]s) under dry and hygrothermal conditions. Damage characteristics are evaluated using various inspection methods and possible damage mechanisms are discussed. Observations demonstrate that as the increase of lightning amplitude, notably enlarged carbon fiber breakage and fiberglass delamination areas as well as fiber bulging are presented in the in-plane and in-depth directions. Compared to a [452/02/-452/902]s carbon woven specimen, the carbon fiber damage area, internal delamination area and damage depth for the hybrid one are 4.94 times, 2.26 times, 3.21 times greater under 22kA lightning strike and 3.34 times, 1.97 times, 1.67 times greater under 32kA strike, respectively. Hygrothermal aging significantly intensifies lightning strike damage on the hybrid specimen with complete detachment of fiberglass layer and massive internal delamination. The possible mechanism for the present damage behavior is analyzed. These results suggest that the fiberglass layer is not expected to protect the integrity of the carbon fiber reinforced polymer structure from lightning strike damage.
Keywords : Hybrid composites; Hygrothermal aging; Ultrasonic inspection; Damage mechanics; Lightning damage
Abstract : This paper experimentally investigates the lightning strike response of a fiberglass/carbon woven hybrid laminate ([(0/90)g(45/02/-452/902)c]s) under dry and hygrothermal conditions. Damage characteristics are evaluated using various inspection methods and possible damage mechanisms are discussed. Observations demonstrate that as the increase of lightning amplitude, notably enlarged carbon fiber breakage and fiberglass delamination areas as well as fiber bulging are presented in the in-plane and in-depth directions. Compared to a [452/02/-452/902]s carbon woven specimen, the carbon fiber damage area, internal delamination area and damage depth for the hybrid one are 4.94 times, 2.26 times, 3.21 times greater under 22kA lightning strike and 3.34 times, 1.97 times, 1.67 times greater under 32kA strike, respectively. Hygrothermal aging significantly intensifies lightning strike damage on the hybrid specimen with complete detachment of fiberglass layer and massive internal delamination. The possible mechanism for the present damage behavior is analyzed. These results suggest that the fiberglass layer is not expected to protect the integrity of the carbon fiber reinforced polymer structure from lightning strike damage.
Keywords : Hybrid composites; Hygrothermal aging; Ultrasonic inspection; Damage mechanics; Lightning damage
