Abstract
This chapter contains a wide discussion about the constitutive axioms. These axioms constitute general rules that any material must satisfy in answering to external agents. The first two of them state that the answer of a material at a point depends, in a certain way, on past history of a neighborhood of that point. The third one is the objectivity principle stating that the response of materials does not depend on the rigid frame of reference adopted to observe their behavior. The fourth is the equipresence principle postulating that, a priori, the fundamental variables of the thermokinetic process influence all the fields describing the answer of the body. Finally, the last one, the dissipation principle, requires that materials, in reacting to the external agents, satisfy the second principle of thermodynamics in any process. In such a way, the entropy inequality becomes a restriction on the constitutive equations rather than a restriction on the processes. The effects of these principles on the constitutive equations are analyzed for thermoviscoelastic materials.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
This problem will analyzed more extensively in Chap. 11.
- 2.
It should be remarked that a material behavior of order 3 is represented by a constitutive response having the structure
$$\displaystyle{\mathbf{A = A}_{C_{{\ast}}}(\mathbf{v,F},\nabla _{\mathbf{X}}\mathbf{F,\dot{F}},\theta,\boldsymbol{\Theta },\dot{\theta },\ddot{\theta },d^{3}\theta /dt^{3},\nabla _{\mathbf{ X}}\boldsymbol{\Theta },\mathbf{X}),}$$where all the third-order derivatives are included. In any case, as shown in Exercise 1, the objectivity principle rules out the dependence on v and the principle of dissipation does not allow any dependence on \(\nabla _{\mathbf{X}}\mathbf{F}\), d 3 θ∕dt 3, \(\nabla _{\mathbf{X}}\boldsymbol{\Theta }\).
References
I-Shih Liu, Method of Lagrange multipliers for exploitation of the entropy principle. Arch. Rat. Mech. Anal. 46, (1972)
I. Müller, The coldness, a universal function in thermoelastic bodies. Arch. Rat. Mech. Anal. 41, (1971)
Author information
Authors and Affiliations
Rights and permissions
Copyright information
© 2014 Springer Science+Business Media New York
About this chapter
Cite this chapter
Romano, A., Marasco, A. (2014). Constitutive Equations. In: Continuum Mechanics using Mathematica®. Modeling and Simulation in Science, Engineering and Technology. Birkhäuser, New York, NY. https://doi.org/10.1007/978-1-4939-1604-7_6
Download citation
DOI: https://doi.org/10.1007/978-1-4939-1604-7_6
Published:
Publisher Name: Birkhäuser, New York, NY
Print ISBN: 978-1-4939-1603-0
Online ISBN: 978-1-4939-1604-7
eBook Packages: Mathematics and StatisticsMathematics and Statistics (R0)