Effect of the fiber-matrix bond on the toughness of soft, short-fiber composites
Abstract
In this work, we investigate toughening mechanisms in soft polymers reinforced with stiff fibers, particularly focusing on the effect of the strength of the fiber-matrix bond on the toughness. We print polydimethylsiloxane with short milled glass fibers using direct ink writing, an extrusion-based 3D printing method. This process produces composites with aligned fibers. Fibers can be treated with acid prior to printing, which improves the strength of the fiber-matrix bond. This results in higher yield stress and toughness. The higher toughness of the composites can be attributed to intrinsic mechanisms such as matrix deformation and fiber pullout, as well as to extrinsic mechanisms like mechanical dissipation. The intrinsic toughness of the composites is analytically estimated using a micro-mechanical model and experimentally measured by stretching the composites in the direction of fiber alignment. Finally, we demonstrate partial healing of the fiber-matrix bond after initial pre-stretch. Thermal treatment of the damaged composites results in partial recovery of stiffness and toughness.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 31, 2023
- Source ID
- 10.1177/00219983231154974
Entities
People
- Chengyang Mo
- Haiyi Long
- Jordan R. Raney
- Rui Yin
Organizations
- Air Force Office of Scientific Research
- University of Pennsylvania