Effect of hygrothermal aging on the damage characteristics of carbon woven fabric/epoxy laminates subjected to simulated lightning strike

This paper investigates the effect of hygrothermal aging on the damage behavior of two stacking sequenced ([45(2)/0(2)/-45(2)/90(2)]s, [30(2)/0(2)/-30(2)/90(2)]s) carbon woven fabric/epoxy laminates subjected to simulated lightning strike. Damage characteristics are evaluated using visual inspection, ultrasonic scanning and scanning electron microscope. The mechanical properties of post-lightning specimens exposed to the dry and the moisture environments are then studied, respectively. Observations show that enlarged resin damage area and delamination region appear for both of the specimens under moisture condition. Compared to the dry conditioned specimens, the fiber damage shape of the moisture treated ones shows a less sensitivity to stacking sequence, which extends along the ply orientation. SEM results show that the fiber/matrix interfacial bonding is severely degraded by moisture and damaged by lightning strike infliction. Mechanical testing further shows that hygrothermal aging has a more significant influence on the residual strength than modulus for the two stacking sequenced specimens. (C) 2016 Elsevier Ltd. All rights reserved.