ADDITIVE MANUFACTURING (AM), COMMONLY REFERRED TO AS 3D PRINTING, IS A BROAD CATEGORY OF TECHNIQUES THAT USE THE ADDITION OF MATERIAL IN A LAYER-WISE FASHION TO...

ADDITIVE MANUFACTURING (AM), COMMONLY REFERRED TO AS 3D PRINTING, IS A BROAD CATEGORY OF TECHNIQUES THAT USE THE ADDITION OF MATERIAL IN A LAYER-WISE FASHION TO FABRICATE SOLID OBJECTS FROM COMPUTER-AIDED DESIGN (CAD) MODELS USING METALS, CERAMICS, SANDS, AND POLYMERS. THE AEROSPACE INDUSTRY HAS BEEN PARTICULARLY DRAWN TO THE ADVANTAGES THAT AM PROVIDES OVER TRADITIONAL METHODS, SUCH AS INCREASED BUILD FLEXIBILITY AND SIGNIFICANT MASS REDUCTION. WHILE WIDE SCALE ADOPTION OF AM FOR THE FABRICATION OF A VARIETY AEROSPACE COMPONENTS IS LIKELY IN THE COMING YEARS, AM IS ALSO BEING EXPLORED AS A MEANS FOR SELF-SUSTAINABILITY AWAY FROM EARTH IN FUTURE PLANETARY EXPLORATION MISSIONS BY USING IN-SITU RESOURCES AS FEEDSTOCK MATERIALS TO PRODUCE TOOLS, SUPPLIES, STRUCTURES, AND OTHER ASSETS. THE PROPOSED WORK SEEKS TO STUDY A PARTICULAR METHOD CALLED BINDER JET ADDITIVE MANUFACTURING (BJAM) TO ADDRESS TWO GOALS PERTAINING TO AEROSPACE APPLICATIONS: (1) TO IMPROVE THE BJAM PROCESS SO THAT

HIGH-FIDELITY, COMPLEX, AND OFTEN ONE-OFF AEROSPACE COMPONENTS CAN BE MANUFACTURED AT MINIMAL COST AND LEAD TIMES, AND (2) TO ASSESS THE VIABILITY OF BJAM AS A METHOD TO PRODUCE FUNCTIONAL PARTS FROM MARTIAN, LUNAR, AND ASTEROIDAL REGOLITH MATERIAL. THESE GOALS WILL BE ACHIEVED THROUGH THE DEVELOPMENT OF A COMPUTATIONAL FRAMEWORK TO SIMULATE THE BJAM PROCESS TO EFFICIENTLY INVESTIGATE THE PARAMETERS THAT LEAD TO OPTIMAL PART PROPERTIES, WHICH WILL REDUCE THE COSTS AND TIME INHERENT WITH TRIAL-AND-ERROR, EXPERIMENTAL APPROACHES. BJAM IS A PARTICULAR TYPE OF POWDER-BED AM PROCESS THAT EMPLOYS A RASTER SCANNING INKJET PRINTHEAD TO ADMINISTER A FLUID BINDER INTO A POWDER LAYER OF A DESIRED MATERIAL TO SELECTIVELY JOIN PARTICLES. THE BOUND PARTICLE CLUSTERS FORM SOLID LINES AND SURFACES THAT MAKE UP A PART CROSS-SECTION IN ACCORDANCE WITH THE GOVERNING CAD MODEL. THIS PROCESS IS REPEATED MANY TIMES WITH EACH CROSS-SECTION SUCCESSIVELY ADDED ON TOP OF THE PREVIOUS ONE UNTIL THE FULL GEOMETRY IS FORMED. BJAM HAS MANY UNIQUE ADVANTAGES COMPARED TO OTHER AM METHODS, SUCH AS ITS WIDE RANGE OF SUITABLE MATERIALS, RELATIVELY FAST BUILD TIMES, AND COST EFFECTIVENESS. THE CHARACTERISTICS OF A COMPONENT PRODUCED BY BJAM ARE A RESULT OF INTERFACIAL FLUID MECHANICS AND PARTICLE DYNAMICS THAT OCCUR WHEN A LIQUID DROPLET IMPACTS A POWDER LAYER. THE RESULTING PARTICLE AGGLOMERATION BOUND FROM A SINGLE BINDER DROPLET IS THE FUNDAMENTAL BUILDING ELEMENT OF THE PART AND IS THE PREDOMINANT FACTOR GOVERNING ITS STRENGTH, DIMENSIONAL ACCURACY, SURFACE PROPERTIES, AND OVERALL QUALITY. ANALOGOUS TO A PIXEL IN A DIGITAL IMAGE, THE PRIMITIVE SIZE AND SHAPE HAS AN IMPORTANT EFFECT ON THE RESOLUTION AND DIMENSIONAL ACCURACY OF THE FINAL PART. IN ORDER TO IMPROVE THE PERFORMANCE OF BJAM COMPONENTS TO MEET THE STRINGENT DEMANDS OF AEROSPACE APPLICATIONS, BETTER UNDERSTANDING OF HOW THIS FLUID-PARTICLE INTERACTION AFFECTS THE QUALITY OF THE FINAL PART IS REQUIRED. THIS WORK SEEKS TO ELUCIDATE THE ROLE OF INTERFACIAL PHYSICS AND FLUID-PARTICLE INTERACTION THROUGH DIRECT NUMERICAL SIMULATION OF THE BJAM PROCESS. COMPUTATIONAL FLUID DYNAMICS (CFD) IS EMPLOYED TO SIMULATE THE FLUID PHASE AND A DISCRETE ELEMENT METHOD (DEM) APPROACH IS TAKEN TO RESOLVE THE PARTICLE DYNAMICS. THE TWO PHASES ARE COUPLED AND THE MOTION OF EACH MUST BE SOLVED SIMULTANEOUSLY. THE CFD ALGORITHM UTILIZES THE VOLUME OF FLUID (VOF) TECHNIQUE FOR CAPTURING MULTIFLUID FLOWS SEPARATED BY A DYNAMIC INTERFACE.
Solicitation ID/Procurement Identifier: 80NSSC19K1171
Ultimate Completion Date: Sat Jul 31 17:00:00 GMT 2021