Post on 24-Feb-2016
description
Instructor: Prof. Yasser Gowayed
Knowledge based problemsFibrous composites
Used with permission
Lecture outline
1. Definition of composite materials2. Types of composite materials3. Fibrous composites4. 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
Laminated Composites
Textile Composite (3D XYZ woven)
Fibrous 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 – naming conventionfor laminated composites
Balanced laminate implies that for every + orientedlayer 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
Terminology – balance and symmetery
The density of any composite is the product of the density of its constituents relative to their volume fraction
c= Vf * f + Vm* m
Vf + Vm = 1
c = composite densityf = fiber densitym = matrix density
Vf = volume fraction of fibersVm = volume fraction of matrix
The rule of mixtures
Composite manufacturing – Compression molding
Fiber/matrix layers
Composite manufacturing - Vacuum bagging
Altitude: 220 n.m. (nominal)Inclination: 51.6 degrees
Dimension: 290 ft (L) x 356 ft (W)
Weight:: 940,000 lbPressurized Volume: 43,000ft3
Power: 110 kW (total); 45kW (users)
International Space Station
FinalConfiguratio
n2004
Textile CMC Turbine Engines
Enabling Propulsion Materials (EPM)CMC Combustor - Lifing & Sub-element Tests
NASA Glenn, Pratt &Whitney and GE