Influence of z-pin length on the delamination fracture toughness and fatigue resistance of pinned composites |
| |
Affiliation: | 1. Advanced Composites Centre for Innovation and Science (ACCIS), University of Bristol, Queen’s Building, University Walk, Bristol BS8 1TR, UK;2. Department of Aeronautics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK;1. Department of Mechanical Engineering, SUNY-Stony Brook, NY, United States;2. Department of Aerospace Engineering, University of Michigan, Ann Arbor, MI, United States;3. Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, United States;4. Department of Aeronautics, Imperial College, London SW7, United Kingdom |
| |
Abstract: | The effect of z-pin length on the mode I and mode II delamination toughness and fatigue resistance of z-pinned carbon-epoxy composites is investigated. Experimental testing and mechanical modelling reveals that both the mode I fracture toughness and fatigue resistance increase with the z-pin length due to increased bridging traction loads generated by elastic stretching and pull-out of the pins. The opposite trend occurs for mode II toughness, which decreases with increasing z-pin length due to lower traction loads arising from restrictions on the shear-induced rotation and pull-out of the pins. The mode II fatigue resistance is increased by z-pinning, although it is not dependent on the z-pin length. Increasing the z-pin length beyond a critical size also changes the mode I and mode II delamination fracture and fatigue processes from single to multiple cracking. The effect of z-pin length on the delamination toughening and fatigue strengthening mechanisms is determined. |
| |
Keywords: | A. Polymer-matrix composites (PMCs) A. 3-Dimensional reinforcement B. Delamination B. Fatigue Pins |
本文献已被 ScienceDirect 等数据库收录! |
|