Failure Analysis and Piezo-Resistance Response of Intralaminar Glass/Carbon Hybrid Composites Under Blast Loading Conditions

In this study, damage mechanisms and the piezo-resistance response of glass/carbon intralaminar hybrid composites are examined under blast loading conditions. Two-ply orientations are considered, namely a repeating ((G45C45)R) and an alternating ((G45C45) A) +/- 45 deg glass/carbon layers, along with three boundary condition configurations: simply supported, partially fixed, and fully fixed are applied. A shock tube apparatus and the three-dimensional digital image correlation technique are utilized to investigate the interaction of shock waves with the composites and gather a comprehensive deformation field during the loading. A modified four-probe resistivity measurement method is implemented to comprehend the piezo-resistance response associated with damage evolution. The results underscore the substantial influence of boundary conditions on the blast mitigation capacity of the composites. Analysis following the experiments reveals that the damage to the specimens primarily involves the fracture of fibers accompanied by internal delamination. Thermal imaging of the tested composite specimens provides enhanced insight into the precise occurrences of internal fiber breakage and delamination. Composites of (G45C45)A type demonstrate an increased energy dissipation ranging from 18% to 33% compared to (G45C45)R composites, depending on the specific boundary conditions among the three types considered. Furthermore, the findings indicated a strong correlation between changes in piezo-resistance and the fracture of carbon fibers, coupled with the sustained deformation of the composites. Notably, (G45C45)A composites exhibited 100-300% higher change in piezo-resistance compared to (G45C45)R composites depending on the boundary condition configurations, indicative of the superior damage-sensing capabilities of the former. [DOI: 10.1115/1.4065763]