STRESS AND STRAIN
STRAIN The effect of stress on a body is named as strain.
LATERAL STRAIN When the deforming force produces a change in length of the given body perpendicular to the direction of force, then the strain produced in the body is called Lateral strain.
VOLUMETRIC STRAIN When the deforming force produces a change in volume of the given body, then the strain produced in the body is called Volumetric strain. It is equal to the ratio of change in volume of a body to its original volume.
Volumetric strain=dV/V
SHEARING STRAIN When the deforming force produces a change in the shape of a body without any change in its volume, then the strain produced in the body is called the Shearing strain.
MODULUS
Young’s modulus: Within the elastic limit, the ratio of stress by strain is called young’s modulus of elasticity.
Rigidity modulus: The ratio of shear stress to shear strain is called rigidity modulus.
Bulk modulus: The ratio of volume stress to volume strain within the elastic limit is called bulk modulus.
POISSON`S RATIO Poisson's ratio is defined as the ratio of the change in the width per unit width of a material, to the change in its length per unit length, as a result of strain.
FRACTURE POINT The fracture point is the point of strain where the material physically separates.
Ultimate tensile strength (UTS), often shortened to tensile strength (TS), is the maximum stress that a material can withstand while being stretched or pulled before breaking.
STRESS the force acting on the unit area of a material
NORMAL STRESS Normal stress when the direction of the deforming force is perpendicular to the cross-sectional area of the body.
LONGITUDNAL STRESS When two cross-sectional areas of the cylinder are subjected to equal and opposite forces the stress experienced by the cylinder is called longitudinal stress.
Longitudinal Stress = Deforming Force / Area of cross-section = F/A
TENSILE STRESS If the deforming force or applied force results in the increase in the object’s length then the resulting stress is termed as tensile stress.
ELASTICITY elasticity, ability of a deformed material body to return to its original shape and size when the forces causing the deformation are removed. A body with this ability is said to behave (or respond) elastically.
HOOKE`S LAW which states that, for relatively small deformations of an object, the displacement or size of the deformation is directly proportional to the deforming force or load.
ELASTIC LIMIT maximum stress or force per unit area within a solid material that can arise before the onset of permanent deformation.