AMIE INDIA Students Forum

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Stress—Strain Behavior Elastic deformation. When the stress is removed, the material returns to the dimension it had before the load was applied. Valid for small strains (except the case of rubbers). Deformation is reversible, non permanent Plastic deformation. When the stress is removed, the material does not return to its previous dimension but there is apermanent, irreversible deformation. In tensile tests, if the deformation iselastic, the stress-strain relationship is called Hooke's law:

[hemlata]

There are thousands of materials available for use in engineering applications. Most materials fall into one of three classes that are based on the atomic bonding forces of a particular material. These three classifications are metallic, ceramic and polymeric. Additionally, different materials can be combined to create a composite material. Within each of these classifications, materials are often further organized into groups based on their chemical composition or certain physical or mechanical properties. Composite materials are often grouped by the types of materials combined or the way the materials are arranged together. Below is a list of some of the commonly classification of materials within these four general groups of materials.

Metals

Ferrous metals and alloys (irons, carbon steels, alloy steels, stainless steels, tool and die steels)
Nonferrous metals and alloys (aluminum, copper, magnesium, nickel, titanium, precious metals, refractory metals, superalloys)
Polymeric

Thermoplastics plastics
Thermoset plastics
Elastomers







Ceramics

Glasses
Glass ceramics
Graphite
Diamond

Composites

Reinforced plastics
Metal-matrix composites
Ceramic-matrix composites
Sandwich structures
Concrete


Each of these general groups will be discussed in more detail in the following pages

[shitalbshinde]

plz tell me in deep about this concept.and how to draw the hexagoanaltwo diamentional lattice .and about three diamentional lattice.