Abstract
This work presents a comprehensive investigation of the elastic and fracture behavior of ply-to-ply angle interlock three-dimensional woven composites. The research investigated novel splitting and wedge-driven out-of-plane fracture tests to shed light on the tensile fracture behavior in the thickness direction and to provide estimates of the out-of-plane tensile strength and fracture energy. In addition, size effect tests on geometrically-scaled Single Edge Notch Tension (SENT) specimens were performed to fully characterize the intra-laminar fracture energy of the material and to study the scaling of structural strength in this type of three-dimensional composites. The results confirmed that size effect in the structural strength of these materials is significant. In fact, even if the range of sizes investigated was broader than in any previous size effect study on traditional laminated composites and two-dimensional textile composites, all the experimental data fell in the transition zone between quasi-ductile and brittle behavior. This implies strong damage tolerance of the investigated three-dimensional composites. The analysis of the data via Bažant's Type II Size Effect Law (SEL) enabled the objective characterization of the intra-laminar fracture energy of three-dimensional composites for the first time. Finally, Arcan rig tests combined with X-ray micro-computed tomography allowed unprecedented insights on the different damage mechanisms under multi-axial nominal loading conditions, particularly tension-dominated and shear-dominated conditions.
Original language | English (US) |
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Article number | 100098 |
Journal | Composites Part C: Open Access |
Volume | 4 |
DOIs | |
State | Published - Mar 2021 |
Funding
The work was partially supported under NSF (Funder ID: 10.13039/100000001) grant No. CMMI-1435923 to Northwestern University. In-kind contribution by Albany Composites is gratefully acknowledged. Dr. Viet T. Chau and Mr. Xin Zhang are acknowledged for participating in the tests discussed in Sec. 3 & 4 and Sec. 5, respectively. The work was partially supported under NSF (Funder ID: 10.13039/100000001) grant No. CMMI-1435923 to Northwestern University. In-kind contribution by Albany Composites is gratefully acknowledged. Dr. Viet T. Chau and Mr. Xin Zhang are acknowledged for participating in the tests discussed in Sec. 3 & 4 and Sec. 5 , respectively.
ASJC Scopus subject areas
- Mechanics of Materials
- Ceramics and Composites
- Mechanical Engineering