Download Introduction to Engineering

Knowledge based problems
Fibrous composites
Instructor: Prof. Yasser Gowayed
Used with permission
Lecture outline
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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)
(45,0,90,-45,90,0,45)
(10,0,45,-45,-10,30,-30)
(45,-45,0,90,0,-45,45)
balanced, un-symmetric
unbalanced, symmetric
balanced, un-symmetric
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
Composite manufacturing - Vacuum bagging
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