Virtual modeling of a manufacturing process to construct complex composite materials of tailored properties

Porous media;Composite;Modeling;Fuel cell;Gas diffusion layer;Transport properties

Didari, Sima ; Harris, Tequila Mechanical Engineering Wang, Yan Nair, Sankar Ghiaasiaan, S. Mostafa Alexeev, Alexander ; Harris, Tequila

University:Georgia Institute of Technology

Department:Mechanical Engineering

关键词: Porous media;    Composite;    Modeling;    Fuel cell;    Gas diffusion layer;    Transport properties;   

Others  :  https://smartech.gatech.edu/bitstream/1853/53410/1/DIDARI-DISSERTATION-2014.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

Fibrousporousmediaarewidelyusedinvariousindustriessuchasbiomedical engineering,textiles,paper,andalternativeenergy.Oftentheseporousmaterialsare formed into composite materials, using subsequent manufacturing steps, to improve their properties. There is a strong correlation between system performance and the transport andmechanicalpropertiesoftheporousmedia,inraworcompositeform. However, thesepropertiesdependonthefinalporestructureofthematerial.Thus,theabilitytomanufacturefibrousporousmedia,inraworcompositeforms,withanengineered structure with predictable properties is highly desirable for the optimization of the overall performance of a relevant system. To date, the characterization of the porous media has beenprimarilybasedonreversedesignmethodsi.e.,extractingthedatafromexisting materials with image processing techniques.The objective of this research is to develop a methodology to enable the virtual generation of complex composite porous media with tailored properties, from the implementation of a fibrous medium in the design space to the simulated coating of this media representative of the manufacturing space. To meet thisobjectiveamodifiedperiodicsurfacemodelisproposed,whichisutilizedto parametrically generate a fibrous domain. The suggested modeling approach allows for a high-degreeofcontroloverthefiberprofile,matrixproperties,andfiber-binder composition. Usingthedomaingeneratedwiththesuggestedgeometricalmodeling approach,numericalsimulationsareexecutedtosimulatetransportpropertiessuchas permeability,diffusivityandtortuosity,aswellas,todirectlycoatthemicrostructure, thereby forming a complex composite material. To understand the interplay between the xxiiifiber matrix and the transport properties, the morphology of the virtual microstructure is characterized based on the pore size, chord length and shortest path length distributions inside the porous domain. In order to ensure the desiredproperties of the microstructure, thefluidpenetration,atthemicroscale,isanalyzedduringthedirectcoatingprocess. This work presents a framework for feasible and effective generation of complex porous media in the virtual space, which can be directly manufactured.