Fatigue damage investigation of PA66/GF30 by X-Ray microtomography

Abstract

Damage behavior of dry as molded, 30 wt% short glass fiber reinforced polyamide-66 (PA66/GF30) under fatigue loading has been investigated by X-ray micro-computed tomography (μCT). Based on visual observation on μCT images, fiber/matrix interfacial debonding is considered as the main fatigue damage mechanism. Void features in the shell and core layer of the μCT 3D images have been identified. The trend of void volume and void aspect ratio shows marked difference on the damage kinetic between the shell and core layer. Though the damage is mainly developed along fiber interface in both shell and core layer, the interfacial debonding in the shell layer appears earlier than the one in the core layer. While the damage at fiber interface in the shell layer develops in all fatigue loaded specimens, the interfacial debonding in the core layer appears only at the very last stage of the fatigue life.