A comprehensive experimental investigation is performed to understand the damage sensing capabilities of thermoplastic intra-ply carbon/glass laminated composites embedded with Carbon Nanotubes (CNTs) under quasi-static interlaminar shear and mode-I fracture loading conditions. CNTs are dispersed in thermoplastic Elium® resin using a combination of ultrasonication and shear mixing processes. This resin mix is used in a vacuum infusion process to fabricate four different intra-ply laminated composites orientations; G-0-C-90 [Carbon fibers are in the longitudinal direction], G-90-C-0 [Glass fibers are in the longitudinal direction], G-45-C-45(R) [carbon and glass fibers are at +45°, and −45° from the longitudinal direction and form a repeating layup], and G-45-C-45(A) [carbon and glass fibers are at +45°, and −45°, but with alternating directions for each lamina in the layup]. Four-circumferential probes are utilized to obtain the piezo-resistance measurements associated with damage inside the composites under shear and mode-I loadings. In the shear experimentation, the G-45-C-45(A) orientation demonstrated the largest interlaminar shear strength, at 50% greater than the G-45-C-45(R) orientation. Both G-45-C-45(A) and G-45-C-45(R) had significantly larger shear strains compared to the G-90-C-0 and G-0-C-90 orientations. However, the best resolution in shear damage sensing was seen with the G-0-C-90 composites. In the mode-I fracture experiments, the greatest fracture initiation toughness is shown with the G-0-C-90 orientation, which is 80% greater than the G-90-C-0 orientation. Compared to all orientations, the G-0-C-90 orientation also provided the most sensitive electrical response.
An experimental study is preformed to investigate the in-situ damage sensing capabilities of intra-ply hybrid carbon/glass laminate and epoxy composites under quasi-static interlaminar shear loading. A three-dimensional electrical sensory network is generated inside the composites through embedded carbon nanotubes (CNTs) in an epoxy matrix along with the carbon fibers in the intra-ply hybrid laminates. CNTs are dispersed in the epoxy matrix using a combination of ultrasonication and shear mixing techniques. Four circumferential ring probes are used to examine the electrical response under interlaminar shear load. The effect of four different intra-ply orientations (((0–90)C, where carbon fibers are oriented along the loading direction), ((0–90)G, where glass fibers are oriented along the loading direction), ((45/−45, where glass and carbon fibers are oriented at 45o/−45oand the laminates are repeated), and ((45/−45)A, where glass and carbon fibers are oriented at 45o/−45oand the laminates are alternated)) on the shear constitutive behavior and the damage detection are discussed. Intra-ply orientations of (45/−45) and (45/−45)Ashowed higher interlaminar shear strength and shear strain at break compared to (0/90)Cand (0/90)Gorientations. Out of all four orientations, (45/−45)Aprovided a better resolution of electrical response for damage sensing applications.
more » « less- PAR ID:
- 10547327
- Publisher / Repository:
- SAGE Publications
- Date Published:
- Journal Name:
- Journal of Composite Materials
- Volume:
- 56
- Issue:
- 2
- ISSN:
- 0021-9983
- Format(s):
- Medium: X Size: p. 213-222
- Size(s):
- p. 213-222
- Sponsoring Org:
- National Science Foundation
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