Abstract
A definition of stability of a body of material under isothermal conditions has been phrased in terms of an external agency which can apply any set of forces to the body. Positive work by each of the sets of forces of the external agency on the change in displacements produced insures stability. The proposal is made now that the external agency be thought of as applying other environmental “forces” with accompanying changes in “displacement”. If temperature change is considered as a force the corresponding change in displacement is the change in the flow of entropy into the body. Attention is devoted to such specialized topics as adiabatic yield surfaces in plasticity and variation of yield stress with temperature. Consideration is given also to the reasonableness of the postulate and to its position in the laws of thermodynamics. One conclusion is that it is necessary to use uncoupled thermal and stress equations in plasticity theory when the yield stress decreases with temperature.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
