02-02-2013, 11:44 AM
Composite –Materials, Manufacturing, and Mechanics (An Introduction)
Composite –Materials,.pdf (Size: 5.25 MB / Downloads: 296)
Overview
Definition and description
Advantages over traditional
materials
History
Challenges and problems
Recent developments
General Definition
Materials system created by combining two
or more individual base materials which
provides a specific set of mechanical and
physical characteristics.
A Few Examples
Fiberglass (glass fibers/polymer matrix)
Carbon fiber composites (carbon fibers/polymer matrix)
Laminated plywood (wood/adhesive)
Corrugated cardboard (paper/adhesive)
Steel reinforced concrete (steel rebar/concrete)
What about metal alloys, ceramics?
Materials Science
A composite is a multiphase material that is artificially
made, as opposed to one that occurs or forms naturally. In
addition, the constituent phases must be chemically
dissimilar and separated by a distinct interface. Thus most
metallic alloys and many ceramics do not fit this
description because their multiple phases are formed as a
consequence of natural phenomena.
Advantages of Composite Materials
over Traditional Materials
Composites have inherent properties that provide
performance benefits over metals. A wide range of fibers
and resins are available to select the optimal material
combination to meet the structural requirements.
Light Weight
Resistance to Corrosion
Resistance to Fatigue Damage
Good Damping Characteristics
Low Coefficient of Thermal Expansion
Can Tailor the Fiber/Resin Mix to Meet Stiffness/Strength/Manufacturing
Requirements
Reduced Machining
Part Consolidation Allows Reduced Number of Assemblies and Reduced
Fastener Count
Tapered Sections and Compound Contours Easily (?) Accomplished
History
WWII –
Sandwich construction used on Mosquito
First fiberglass boat molded, no parting agent used (1942)
Laminates of cloth-filed phenolic used in bomb tubes and bazooka barrels (1943)
Post War developments
Epoxy introduced commercially in the U.S. as an adhesive (1947)
Honeycomb fuel cell support panels used in B-36 bomber (1949)
First metal-to-metal adhesives used in aircraft primary structures (UK)
Experimental Spitfire fuselage fabricated of flax fiber and phenolic resin (UK)
Full scale wing spar constructed of flax fiber and phenolic resin for a Bristol
"Blenheim" bomber (UK) (
High-strength and high modulus, S-glass and boron fibers developed (1960)
Graphite fibers become available for research (1964)
First application of FRP in high temperature aircraft structure, F-111 (1965)
First advanced composite part designed and produced, F-14 (1969)