Opportunity at Air Force Research Laboratory AFRL
Performance Prediction and Damage Prognosis of Structural/Multifunctional Composites
Materials & Manufacturing, RX/Structural Materials Division
||Wright-Patterson AFB, OH 454337817
|Craig P Przybyla
Although the use both structural and multifunctional composites continues to increase, substantial obstacles exist to successfully couple the plethora of obtained microstructure, experimental, and simulation data for accurate life prognosis. In general, continuous fiber reinforced composites (RFCs) are complex hierarchical materials whose response is a function of various attributes at multiple length scales. Multiple regimes of crack initiation and propagation have been observed depending on constituent materials, fiber architecture, and defect populations. Moreover, environmental degradation modes can accelerate crack growth and eventual failure. The challenge is even more exacerbated by newer composite variants intended for use in extreme environments. For example, continuous fiber SiC fiber reinforced SiC matrix composites are targeted for use in gas turbine jet engines at temperatures >1315C. There is currently a lack of understanding of several fundamental mechanisms: degradation and failure at the length scale of the dominant microstructural features, the interaction and coupling of mechanisms across length and time scales, the kinetics of the oxidation processes at higher temperatures, the dependence of functional response on mechanical loads, and the physics of the interaction of the thermal-acoustic-mechanical-oxidation environments on damage. Many opportunities exist to pursue multiple experimental and or modeling solutions to help solve these issues. Our facility offers a variety of state-of-the-art experimental and computational resources to help address these problems.
Braginsky M, Przybyla CP: “Simulation of crack propagation/detection in ceramic matrix continuous fiber reinforced composites with weak interphase via the extended finite element method.” Composite Structures, 136: 538-545, 2016
Iarve EV, et al: "Mesh-independent matrix cracking and delamination modeling in laminated composites." International Journal for Numerical Methods in Engineering 88: 749-73, 2011
Polymer matrix composites; Ceramic matrix composites; Multifunctional composites; Discrete damage modeling; Microstructure-sensitive; Fatigue; fracture; Environmental degredation; Multiphysics;
Open to U.S. citizens
Open to Postdoctoral and Senior applicants
$3,000 Supplement for Doctorates in Engineering & Computer Science
Postdoctoral and Senior Associates will receive an appropriately higher stipend based on the number of years of experience past their PhD.