05-10-2012, 01:59 PM
Composite Materials for Aircraft Structures
Composite Materials.pdf (Size: 2.11 MB / Downloads: 338)
Introduction
• Composite materials are used more and more for
primary structures in commercial, industrial, aerospace,
marine, and recreational structures
Composites:
• Composites materials consist of a fibrous reinforcements
bonded together with a matrix material
• Occur naturally in your bones, in wood, horns etc.
• Allow the stiffness and strength of the material to change
with direction of loading
The Hierarchy for Advanced Structural Materials
• Begin as laboratory curiosity
• Applications to expensive structures (often Military
Aerospace)
• Applications to stuff rich people buy
• Applications to things you and I can afford
Key Assumption: Raw materials are ultimately
inexpensive and materials synthesis is ultimately
inexpensive
Case History- Aluminum
• At one time, more rare than gold and silver; Kings
and Queens wanted aluminum plates
• Very Expensive Applications
– Art Deco furnishings in the 1920s and 1930s
– Military aircraft during WW II
• Stuff that rich people buy (Post WW II through 1960s)
– General Aviation
– Boats
– Bicycles
• Today
– Aluminum BBQ grills at K-Mart
– Aluminum shower curtain rods at hardware store
Summary
• Composite parts used for aircraft applications are defined by
– Material, process, and manufacturing specifications.
– Material allowable (engineering definition).
• All of these have a basis in regulatory requirements.
• Most efficient use of advanced composites in aircraft
structure is in applications with
– Highly loaded parts with thick gages.
– High fatigue loads (fuselage and wing structure, etc).
– Areas susceptible to corrosion (fuselage, etc).
– Critical weight reduction (empennage, wings, fuselage, etc).
• Use must be justified by weighing benefits against costs.