Dynamic Fatigue and Fracture of Woven Polymer Matrix Composites under Combined Mechanical-Environmental Loading
Abstract
Dynamic Fatigue and Fracture of Woven Polymer Matrix Composites underCombined Mechanical-Environmental LoadingPI: Leslie Elise Lam"berson, Drexel University; Total Budget: $382,369.71Naval aviation is on the forefront of maritime forces, with sea-based demandsr""equiring robust materials and structures that necessitate increased damage resistanceunder complex loading life cycles. As such, ai"rcraft structures and associated navalmaterials are pushed to their limits in terms of multi-axial and multi-temporal loadingcondi"tions, often dynamic (i.e. transient and high-rate) and in moist environments withcorrosion concerns owing to the presence of seawa""ter. By taking advantage of polymermatrix composite materials (PMC~s), including carbon fiber and glass fiberreinforcements,the ab""ility to design these structures with reduced weight, number offasteners, radar cross-section, and increased corrosion resistance,"" along with thepotential for extended life and durability over their metallic counterparts, now exists.At the same time, the optim""ization of PMC design in airframe structures has not beenfully realized, largely due to the difficulty (and novelty) of the experim""ental suiteneeded to systematically and accurately evaluate anisotropic microstructure in complexloading environments, combined wi"th the challenge in establishing correspondinganalytical theory for failure criterion from the empirically evaluated physical quant"ities.Consequently, the goal of this project is to overcome the technical andanalytical challenges in developing predictive dynami"c fatigue and fracture criterion;and hence quantify damage of woven polymer matrix composites under combinedmechanical-environment"al loading conditions of direct relevance to the Navy.Specifically, the work will focus on the effect of moisture and corrosion in"unidirectional carbon fiber and woven fiberglass composites of varying thermosettingresins under three regimes: multi-axial stress" states for strength characterization,mixed-mode anisotropic dynamic fracture, and impact fatigue. The novelty of the worklies in"" the combination of unique experimental capability, leveraging full-field opticaltechniques and ultra high-speed imaging, along wit"h the synergistic analytical objectivein developing of a rate-dependent damage model that will evolve and improve based onthe empi"rical results. The model combines an existing nonlinear time-dependentmaterial model (Bodner-Partom, a viscoplastic model originall""y derived for metals andextended to woven PMC s), with an interacting dynamic microcrack damage model(Pailwal-Ramesh). Due to the"" inherent and critical influence of woven MC~smicrostructural character including initial flaws, environmental sensitivity inconst""ituent degradation, and flaw evolution on its macroscopic response, careful preandpost-mortem microscopy and x-ray tomography will" be synergistically pursued.The objectives of this proposal are to develop new frameworks to accuratelyassess the damage of PMC~s as a function of microstructure and environmentalconditions in the relevant dynamic regimes of uniform plane strain biaxial compre"ssion,non-uniform plane stress impact, and the accumulation of sub-failure repetitive impactson hysteretic response; extending bey"ond traditional first-order quasi-staticexperimental identification. Success of these endeavors will improve the predictiveaccurac"y of relevant computational structural models, shed light on tailoring PMCmicrostructures for particular applications, and provide" benchmark experimental resultsfor the design and use of woven PMC~s in naval aviation applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 05, 2017
- Source ID
- N000141712497
Entities
People
- Leslie Lamberson
Organizations
- Drexel University
- Office of Naval Research
- United States Navy