Microscale Investigation of the Compressive Behavior in Unidirectional PMCs Through In-situ SEM and X-ray CT Experiments

Abstract

Experimental compressive studies have been carried out on unidirectional carbon fiber composite samples at the sub-ply scale in order to observe failure mechanisms within the microstructure. The experiments were conducted in-situ within an SEM and X-ray μCT using a specially designed fixture allowing the same test to be conducted in both instruments without removing the test specimen. The combination of testing in SEM and CT allow for the gathering of high resolution images suitable for DIC during loading from SEM imaging and complete deformation understanding achieved through CT scans under load. Observed out of plane deformation through X-ray CT, proved essential to understanding the deformation. The testing scope of this project is from samples containing a handful of fibers to scores of fibers in order to link compressive failure to fiber micro buckling, global buckling, or crushing and fiber failure. Image analysis from CT reconstructions has been applied to track fiber rotation while in a deformed loading state and allow an exact model of the sample to be generated as the fiber locations throughout the sample are known.