On Cauchy's stress theorem
In this work a new proof of the theorem of Cauchy on the existence of the stress tensor is given which does not use the tetrahedron argument.
In this work a new proof of the theorem of Cauchy on the existence of the stress tensor is given which does not use the tetrahedron argument.
In classical constitutive models such as the Navier-Stokes fluid model, and the Hookean or neo-Hookean solid models, the stress is given explicitly in terms of kinematical quantities. Models for viscoelastic and inelastic responses on the other hand are usually implicit relationships between the stress and the kinematical quantities. Another class of problems wherein it would be natural to develop implicit constitutive theories, though seldom resorted to, are models for bodies that are constrained....
This article defines and presents the mathematical analysis of a new class of models from the theory of inelastic deformations of metals. This new class, containing so called convex composite models, enlarges the class containing monotone models of gradient type defined in [1]. This paper starts to establish the existence theory for models from this new class; we restrict our investigations to the coercive and linear self-controlling case.
The Mori-Tanaka effective stiffness tensor is shown to be asymmetric in general. This tensor is proven to be symmetric for composites with isotropic inclusions, or with spherical reinforcements. Symmetry is also proven for the case of unidirectional fibers, of any shape and material. The Mori-Tanaka theory is shown to yield physically unacceptable predictions at the high concentration limit.