Patrik Fernberg

The weight loss and damage development of satin weave and thin‐ply carbon fiber‐reinforced polyimide composites are studied during high temperature (288 and 320°C) aging in air. Two distinct regions are identified in the weight loss measurements—a rapid initial desorption and a subsequent slower weight loss, which is attributed to matrix degradation. The initial desorption stage is modeled by combining material constitutive properties from literature, micro‐mechanics and a one‐dimensional Fickian diffusion model. Two different damage patterns are observed by using optical microscopy and X‐ray computed tomography on specimens before and after aging. Crack clusters form a network in satin weave composites, while edge delaminations are observed in thin‐ply laminates, which are known for their enhanced resistance to matrix cracking.