Novel Multi-scale/Multi-physics Integrated Tool for the Prediction of Manufacturing-Induced Defects in Autoclave Composite Airframe Parts Navy STTR FY2015.A Sol No.: Navy STTR FY2015.A Topic No.: N15A-T003 Topic Title: Novel Multi-scale/Multi-physics Integrated Tool for the Prediction of Manufacturing-Induced Defects in Autoclave Composite Airframe Parts Proposal No.: N15A-003-0189 Firm: Global Engineering and Materials, Inc. 1 Airport Place, Suite 1 Princeton, New Jersey 08540-1532 Contact: Jeong-Hoon Song Phone: (303) 735-0363 Web Site: www.GEM-Innovation.com Abstract: A multi-scale/multi-physics integrated tool will be developed to virtually and qualitatively predict the manufacturing defects in structural thermoset polymer composites through a first-principles based approach. The chemo- and thermo- mechanical properties of the thermoset resin during the autoclave process will be characterized with a reactive force field full atomistic and coarse-grained molecular dynamics. A physics-based mapping between these atomistic properties and the actual autoclave processing parameters will be established through the response surface-based reduced order modeling techniques. Then this physics-based mapping will be adopted in the micro- and macro-continuum level analysis to predict fabrication-induced defects. Through this combined multi-scale/multi-physics approach, a macroscopic defect-distribution map will be created with the indication of defects occurrence of various types in composite product level; note that this information will serve as an initial manufacturing-induced material damage for further damage growth/interaction analysis via the XFEM approach. During the process, extensive verification and validation will be conducted to ensure the accuracy of the multi-scale/multi-physics integrated tool on predicting actual damage distributions. GEM has already secured commitments for technical, verification and validation supports from University of Colorado, Lockheed Martin, NRL, and NIAR for the success of the proposed work. Benefits: The research will result in a versatile, user-friendly, and computationally efficient toolkit for autoclave process simulation, characterization of thermomechancal properties of resin, probabilistic initial damage description in terms of a defect-distribution map, characterization of damage state at a Gaussian point of a macro-continuum element, and performance of design and certification of composite structures with the initial fabrication-induced defects. Our team members Lockheed Martin, NRL and NIAR have already indicated interest in applying the toolkit to optimize the fabrication of unitized composite structures. As a key player of the Integrated Computational Materials Engineering (ICME), LM Aero has envisioned the potential of the physics-based tools for understanding the formation of defects in composite laminates during autoclave curing. NIAR has fabricated large scale laminated composite structures using their autoclave facilities. It is extremely difficult to eliminate all the fabrication-induced defects (voids, delamination, resin rich areas, and foreign inclusions) using the suppliers�_ curing specification and their experience. Therefore, the toolkit developed by our proposed approaches, which enables the optimal selection of fabrication parameters to reduce the level of the fabrication-induced defects and certify the fabricated structure in the presence of the initial defects, is of significant importance to the composites manufacturing industries. Return