The influence of through-thickness reinforcement geometry and pattern on delamination of fiber-reinforced composites: Part II – Modeling. (1st December 2017)

• Record Type: Journal Article
• Authors: Pappas, Georgios; Joncas, Simon; Michaud, Véronique; Botsis, John
• Is Part Of: Composite structures. Volume 181(2017)
• Page Start: 379
• Page End: 390
• Publication Date: 2017-12-01
• Subjects: Composite materials -- Fracture resistance -- Through-thickness reinforcement (TTR) -- Tufting -- Traction separation relations -- Cohesive zone modeling; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2017.08.096
• Languages: English
• ISSNs: 0263-8223

Abstract

Abstract: This article reports modeling techniques and results based on experimental Mode I characterization of a layered woven GFRP material with tufting reinforcement. Standard tuft and loop-less geometries are investigated on three different areal patterns to evaluate their effects on fracture resistance. The experiments reveal that tow/ply and tuft bridging phenomena are present during delamination. The numerical modeling comprises cohesive elements for tow/ply bridging and 1D connector elements for discrete tufts. The traction separation relations for the cohesive model are acquired using an inverse scheme based on strain measurements and the force-separation relations of tuft's failure mechanisms from uniaxial pulling tests on a reference tufting pattern. Results show that tuft's failure mechanism is strongly affected by tufting pattern and geometry while tow/ply bridging contributes 20–30% of the overall fracture energy. The energy absorbed by pull-out of loop-less tufts is approximately twice the fracture energy of standard ones with pull-out triggering much more extensive tow/ply bridging phenomena.