Title: Adhesively Bonded Composite Durability (ABCD) Phase 3

Authors: Jason Action, Carl Rousseau, and Jeffery Scheinost

DOI: 10.33599/nasampe/s.19.1632

Abstract: The Adhesively Bonded Composite Durability (ABCD) program is a multi-phased effort by the Office of Naval Research (ONR) to address the concerns of bonded composite joints as major structural load paths. The initial phase of the program performed a gap analysis on current material methods and analysis technologies that would support the design guidelines of the Joint Service Specification Guide (JSSG-2006). Phase 2 advanced two of the items identified in the gap analysis, a fail-safe life limit (FSLL) analysis and the further development of allowable test methods to support bonded primary joints. The current phase 3 of the program focuses on closing the gaps in the two selected areas of the prior phase. The FSLL efforts will address the assumptions built into the analysis, such as the use of Miner’s rule and fatigue crack growth characteristics like path, shape, and mode mixity. This will be achieved through the fatigue testing and analysis of a bonded element that incorporates many aspects of a joint seen in aircraft design. An additional goal of the analysis in this phase is display the ability to determine the residual strength of the bonded joint after it has experienced a determined amount of life. The allowable test method development effort will include maturation of a Mode II fatigue test to determine fatigue delamination onset and growth characteristics, maturing a Mode III test method, developing mixed mode crack growth data that incorporates mode III effects, and overall interlaminar fracture testing of fabric materials in all failure modes.

References: 1. ""Joint Service Specification Guide"", JSSG-2006, Oct. 1998. 2. Benzeggagh, M.L., and Kenane, M., “Measurement of Mixed-Mode Delamination Fracture Toughness of Unidirectional Glass/Epoxy Composites with Mixed-Mode Bending Apparatus”, Composites Science and Technology, Volume 56, 1996, pp. 439-449. 3. “Standard Test Method for Measurement of Fatigue Crack Growth Rates” ASTM E647-15, 2015. 4. J. Reeder, “3D Mixed-Mode Delamination Fracture Criteria - An Experimentalist’s Perspective,"" in Proceedings of American Society for Composites, 21st Annual Technical Conference, Dearborn, Michigan, 2006. 5. “Characterization of In-Plane, Shear-Loaded Adhesive Lap Joints: Experiments and Analysis” DOT/FAA/AR-03/21, May 2003. 6. “Standard Test Method for In-Plane Shear Properties of Polymer Matrix Composite Materials by the Rail Shear Method” ASTM D4255/D4255M-15A, 2015.

Conference: SAMPE 2019 - Charlotte, NC

Publication Date: 2019/05/20

SKU: TP19--1632

Pages: 14

Price: FREE