Damage Evolution Analysis on Compression-Loaded Multidirectional Carbon Fiber Laminates Using Ex-Situ CT Scans

Abstract

Damage evolution inside compression-loaded laminates is a crucial aspect when design-ing crash structures. In this study, ex situ CT scanning is used to identify damage evolution in multidirectional composite laminates. Multiple CT scans throughout the stress–strain envelope are used to quantify the internal damage and failure propagation of a [45, −45, 90]s carbon fiber laminate. Initially, observed damage occurs in form of delamination between the −45◦ and 90◦ layers. Afterward, shear failure propagates from the central layers throughout the entire laminate. Shear failure in the middle two layers expands after continued loading up to double shear failure. The same distinct failure sequence is observed in multiple specimens, and the small deviation supports consistency. Furthermore, the stress–strain envelope of the successive load cycles matches closely with reference measurements.