Morphology characterization and in-situ three-dimensional strain fi eld monitor of short carbon fi ber -reinforced polymer composites under tension

In-situ Micro X-ray computed tomography (?CT) offers a new opportunity to monitor the 3D morphology and damage evolution of short carbon fiber-reinforced polymer (SCFRP) composite. However, the sample size of in -situ ?CT is generally limited to achieve high revolution, which resulted in different mechanical behavior compared with that obtained from standard samples. In this study, ?CT scans with two resolutions were combined to character the 3D geometrical morphology and monitor the 3D deformation fields of SCFRP composites under tension. High resolution ?CT scans with voxel size of 0.68 ?m were used to quantify the geometric characteristics of fibers and void defects inside small samples. Low resolution in-situ ?CT scans with voxel size of 4 ?m and digital volume correlation method were utilized to monitor the 3D deformation fields of standard specimens under tension. The failure behavior of SCFRP was determined by the micro geometric morphology. The fracture surface under tension is oriented along 120? and 240? in the XY plane, which is consistent with the fiber and debonding distribution.

Automated summary

By combining high and low resolution ?CT scans, this study successfully monitored the 3D geometric morphology and deformation fields of SCFRP composites under different tension states, and determined the influence of micro geometric morphology on material fracture behavior.