modulus of elasticity The ratio of the stress applied to a body to the strain that results in the body in response to it. The modulus of elasticity of a material is a measure of its stiffness and for most materials remains constant over a range of stress. ◇ The ratio of the longitudinal strain to the longitudinal stress is called Young's modulus. ◇ The ratio of the stress on the body to the body's fractional decrease in volume is the bulk modulus. ◇ The ratio of the tangential force per unit area to the angular deformation in radians is the shear modulus. See also Hooke's law. |