X-Ray Computed Tomography for Nondestructively Inspecting Damage Initiation and Growth Mechanics of Composites and Bonded Joints under Fatigue Loading
Abstract
Due to heterogeneous microstructure, fatigue damage growth mechanics of composites arecomplex and highly dependent on the type of loading mode and load sequencing. Similarly, thebonded joints, especially with composite adherends, have complex multi-mode failures, but thesequence of failure events is not well understood. Final destructive failure mode tends toovershadow damage initiation sites and propagation details in composites and bonded joints.Therefore, a high-fidelity 3D inspection technique such as X-ray Computed Tomography (CT) isrequired to investigate the damage growth mechanics and interaction of multiple failure modes.Detailed CT inspections of as-manufactured defects/features can be used for developingrepresentative volume elements (RVEs) depicting the initial state of the material for investigatingeffects of defects on strength and durability. Furthermore, periodic CT inspections conductedduring fatigue testing can be used to validate predictions of multi-scale multi-physics fatigueanalysis techniques. Bonded joints tend to have catastrophic failure during fatigue without anynoticeable indications. CT can be used to determine damage caused by load redistribution due tofatigue wearout and damage precursors, because such fatigue phenomena may not be evidentusing standard NDI techniques or stiffness checks. Principal investigators have partnerships forseveral Navy SBIR/STTR projects related to characterization of effects of manufacturing defectsand fatigue damage growth mechanics of composite bonded and bolted joints. CT will be usedfor detailed inspections required for these research programs in order to support the developmentof high-fidelity multi-scale multi-physics progressive damage growth analysis models as well asto conduct failure analysis (failure initiation and progression), which will be beneficial fordesign, fabrication, and maintenance of future DoD composite applications. The knowledgegained through CT will enhance researchers~/students~ understanding of material behavior andwill be helpful for future proposal developments.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2017
- Source ID
- N000141712070
Entities
People
- Waruna Seneviratne
Organizations
- Office of Naval Research
- United States Navy
- Wichita State University