Yield Point depends on the Rate of Strain. Its Theory

Abstract

It is now recognized as a well-known fact that the yield point depends on the rate of strain as a result of the investigations by Ludwik, Manjoine and other investigators. The author presents a new theory in order to explain this phenomenon and expresses it by a model which consists of two springs, two dashpots and one friction block. The arrangement of these component parts in this model is somewhat different from any other model used widely in the field of rheology. The relation among the stress, the strain and the rate of strain is expressed by the following equations in this theory : σ=Eε₆+Bε^^·_p and Eε₆=D+Bε^^·_p where σ means the stress, ε_e, the elastic strain, ε^^·_p, the rate of strain and D is the force acting on the friction block..