THERMODYNAMICS OF MATERIALS WITH MEMORY.
UTAH UNIV SALT LAKE CITY COLL OF ENGINEERING
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A continuum thermodynamic theory of nonlinear thermomechanical materials with memory is developed and its application to the observed behavior of real materials discussed. Following a review and summary of the basic concepts of modern continuum mechanics an in-depth discussion and appraisal of the axiomatic foundations of thermomechanical constitutive theory is presented. An extended principle of equipresence is proposed which appears to be necessary for the rigorous axiomatic development of thermomechanical constitutive theories. A new physical principle of fading memory is next introduced which extends previous principles of fading memory to include finite memory and permanent memory. Coupling between memory effects under different loading situations is allowed. Colemans continuum thermodynamic theory is also extended to admit materials and processes capable of instantaneous dissipation. With these extensions, the constitutive theory developed herein admits classes of materials and processes which are more closely related to the observed physical behavior of real materials under a variety of loading environments. In particular, the constitutive theory is directly applicable to viscoelastic solids, inelastic deformations such as plasticity and viscoplasticity, and reduces to previous special theories of idealized materials under appropriate simplifying assumptions. Author