Strain
*Deformation per unit length in the direction of deformation is known as strain.
*Stresses acting on the material cause deformation of the material. Deformation of the material is called strain.
*It has no units and dimensions.
TYPES OF STRAINS
1.Longitudinal strain
2.volume strain
3.shearing strain
1.Longitudinal Strain
*It is the ratio of the change in length of a body to the original length of the body.
2.Volume strain
It is the ratio of the change in volume of a body to its original volume.
3.Shear Strain
If is the angle through which a face originally perpendicular to the fixed face is turned. (or) It is the ratio of the displacement of a layer to its distance from the fixed layer.
NOTES
Corresponding to the three types of strain, there are three moduli of elasticity.
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Young's modulus, corresponding to longitudinal strain,
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Bulk modulus, corresponding to volume strain and
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Rigidity modulus, corresponding to shearing strain.