ISSN:
1089-7550
Quelle:
AIP Digital Archive
Thema:
Physik
Notizen:
A nonequilibrium thermodynamic theory for predicting the mechanical behavior of materials beyond the elastic range is formulated. The theory incorporates the idea of a "concealed'' parameter α, originally due to Bridgman [Rev. Mod. Phys. 22, 56 (1950)], where the constitutive equations are governed by (a) a thermodynamic potential such as a generalized Gibbs function, G, or Helmholtz free-energy function, F, each with an explicit dependence on α, and (b) a prescription for α(overdot), the time rate of change of α, such that α(overdot) is directly proportional to the negative of Gα or Fα, the partial derivative of G or F with respect to α, respectively. The theory is found to be consistent with (1) the second law of thermodynamics regarding entropy production; (2) the concept of Lyapunov stability at equilibrium; (3) the rule of invariance with respect to a transformation of parameters; and (4) the powerful law of invariance with respect to the Legendre transformation. Significance of the new formulation is discussed by solving a class of one-dimensional creep and fatigue modeling problems and by comparing the new theory with several similar approaches in the literature.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.354703
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