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Knowledge based problems Fibrous composites. Instructor: Prof. Yasser Gowayed. Used with permission. Lecture outline . Definition of composite materials Types of composite materials Fibrous composites Textile composites. Definition.
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Knowledge based problems Fibrous composites Instructor: Prof. Yasser Gowayed Used with permission
Lecture outline • Definition of composite materials • Types of composite materials • Fibrous composites • Textile composites
Definition Composite materials are made by mixing two or more distinct materials, having a macroscopically recognizable interface
Types of Composite Materials • Type of inclusion • spheres, rods, fibers, flakes • Type of material • - Polymer Matrix Composites (PMC) • - Ceramic Matrix Composites (CMC) • - Metal Matrix Composites (MMC)
Fibrous Composites • Fibers: strong and flexible • Matrix: rigid and inert
Fibrous Composites Laminated Composites Textile Composite (3D XYZ woven)
Terminology – naming convention for laminated composites • Common industry practice to use angles to name layers: 0, 45, -45, 90 • Laminates with similar number of like orientations share similar properties • Naming convention: • (0/45/90/90/-45/-0) • (0/45/90)s
Terminology – balance and symmetery Balanced laminate implies that for every + oriented layer there exists a - oriented layer of the same material (45,0,90,-45,0,90) balanced, un-symmetric (45,0,90,-45,90,0,45) unbalanced, symmetric (10,0,45,-45,-10,30,-30) balanced, un-symmetric (45,-45,0,90,0,-45,45) balanced, symmetric
The rule of mixtures The density of any composite is the product of the density of its constituents relative to their volume fraction rc= Vf * rf + Vm* rm Vf + Vm = 1 rc = composite density rf = fiber density rm = matrix density Vf = volume fraction of fibers Vm = volume fraction of matrix
Composite manufacturing – Compression molding Fiber/matrix layers
International Space Station Altitude: 220 n.m. (nominal) Inclination: 51.6 degrees Dimension: 290 ft (L) x 356 ft (W) Weight:: 940,000 lb Pressurized Volume: 43,000ft3 Power: 110 kW (total); 45kW (users) Final Configuration 2004
Enabling Propulsion Materials (EPM) CMC Combustor - Lifing & Sub-element Tests Textile CMC Turbine Engines NASA Glenn, Pratt &Whitney and GE