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**Inelastic behavior of materials. II: Energetics associated with discontinuous deformation twinning.**
*(English)*
Zbl 0905.73002

Following part I [the authors, ibid. 11, No. 6, 653-678 (1995; Zbl 0858.73006)] devoted the development of a macroscopic theory to model the inelastic deformation twinning of polycrystals, we provide in this paper a thermomechanical framework for the study, albeit under the assumption that the process is isothermal. A criterion based on energetics is proposed for the initiation and propagation of twinning. The theory is based on the notion of multiple natural configurations. We bring out the important role played by the dissipative processes on the onset and arrest of twinning. We show that the entire constitutive structure of the material can be reduced to the specification of three scalar functions to model “quasi-equilibriated deformation twinning’: the Helmholtz potential \(\psi\), the rate of dissipation function \(\xi\) and the activation function \(g\).

### MSC:

74A20 | Theory of constitutive functions in solid mechanics |

74C99 | Plastic materials, materials of stress-rate and internal-variable type |

74A15 | Thermodynamics in solid mechanics |