A NEW FORM OF THE COHERENCY ENERGY IN PSEUDOELASTICITY

In some previous papers [1], [2] pseudoelasticity in tensile experimen ts has been treated thermodynamically under the assumption that the re levant constitutive ingredients are (i) a non-convex free energy; (ii) coherency between the austenitic and martensitic phase. The form of t he coherency energy was assumed to be proportional to the product of p hase fractions of the two phases. Recently Rogers [3] has proposed a s light variation of this ansatz: The factor of proportionality should d epend on the transformation strain. This new form of coherence energy is investigated in this paper. An attractive feature of this new assum ption is that the strains of the coexisting phases in equilibrium rema in unchanged as the transformation proceeds. The entropy production in side the pseudoelastic hysteresis is explored for various straight (P, d)-curves.