04-02-2013, 12:41 PM
Yield Theory Postulated By BELTRAMI & HAIGH
Introduction:-
The theory states that “ Inelastic action at any point in a body due to any state of stress begins ,only when the energy per unit volume absorbed at the point is equal to the energy absorbed per unit volume of the material ,when subjected to the elastic limit under a uniaxial state of stress, as occurs in a simple tensile test”
According to this theory, a body under complex stresses fails when the total strain energy in the body is equal to the strain energy at elastic limit in simple tension.
Strain Energy : Work done by load provided no energy is added or subtracted in the form of heat.
LIMITATIONS OF THIS THEORY:-
This theory is derived by testing on ductile material, however it is not applicable to brittle material which are having totally different inelastic stress in compression & tension.