ABSTRACT
Consider a body initially in a stress-free, strain-free state of mechanical and thermal oequilibrium at the uniform temperature T . Subsequently, the body is subjected to
external loads as a result of which it deforms and reaches a second state of mechanical 1 2 3equilibrium at some known temperature distribution T(x , x , x ). We define the following
quantities for this body:
1 2 31. A statically admissible stress field (x , x , x ) (i, j = 1, 2, 3) in the body in the
deformed state of mechanical equilibrium is one which satisfies the requirements for equilibrium of its particles. This implies that the statically admissible components of stress have the following attributes:
(a) They have first derivatives at every point inside the volume of the body. (b) They are symmetric . This ensures that the sum of the moments of all
the forces acting on each particle of the body vanishes. (c) They satisfy the equations of equilibrium (2.69) at every point inside the volume
of the body. This ensures that the sum of all the forces acting on each particle inside the volume of the body vanishes.
