02-05-2013, 12:41 PM
Composite materials on aerospace application
Composite materials.ppt (Size: 2.09 MB / Downloads: 208)
INTRODUCTION
WHAT IS MATERIALS ?
Material is anything made of matter, constituted of one or more substances. Wood, cement, hydrogen, air and water are all examples of materials. Sometimes the term "material" is used more narrowly to refer to substances or components with certain physical properties that are used as inputs to production or manufacturing. In this sense, materials are the parts required to make something else, from buildings and art to stars and computers.
DISADVANTAGES:
Metals lose their strength at elevated temperatures .
High-polymeric materials in general can withstand still lower temperatures.
Ceramics outstrip metals and polymers in their favourable melting points , ability to withstand high temperatures ,strength and thermal expansion properties, but due to their brittleness they are often unsatisfactory as structural materials.
COMPOSITES:
Composite materials can be defined as the materials which consists of a mixture or combination of two or more micro constituents mutually insoluble and differing in form and/or material composition.
Examples :-
steel reinforced concrete (metals+ceramics)
vinyl-coated steel (metals+polymers)
fibre reinforced plastics (ceramics+plastics)
CHALLENGES OF USING COMPOSITES :
Composites are not only new but also Non-conventional :
Anisotropic
Inhomogeneous
Have different fabrication
Have different Working methods
Have different Controls for quality assurance
Have Complex material behaviour under load requiring new and complicated analysis tools.
Moreover, the behaviour is not always predictable by analysis and this makes reliance on several expensive and time consuming tests unavoidable.
ROUTES TO MEET THESE CHALLENGES:
Use of Advances in computer technology and analysis methods to implement schemes based on
Computer aided design
Computer aided engineering
Finite element methods of analysis
Building computer interfaces amongst all aspects of development, namely, design and manufacturing.
These should provide fast transfer of information including graphics and accurate analysis methods for a reasonable prediction of complex behavioural patterns of composites.
CONCLUSION :
Hence we can finally conclude that :
Composite materials offer high fatigue and corrosion resistance.
Composite materials have high strength to weight ratio.
So they are best suited for various aerospace applications.