introduction: nano-indentation has recently been employed as a powerful tool for determining the mechanical properties of biological tissues on nano and micro scales. a majority of soft biological tissues such as ligaments and tendons exhibit viscoelastic or time-dependent behaviors. the constitutive characterization of soft tissues is among very important subjects in clinical medicine and espe...

We report results concerning the treatment of elastic bodies described by implicit constitutive relations which are not solvable, in the sense of expressing the stresses as functions of the strains or vice versa. Motivated by the theory of generalized hyperelastic materials, which applies also to polyatomic crystals, the field equations to be solved for a body described by a non-solvable implic...

The ultimate objective of this research project is to develop creep damage constitutive equations for low Cr-Mo alloy and its weldment under low stress (0.2-0.4 yield stress, ��). This paper summarizes a critical analysis on the cavity nucleation and growth and the deformation mechanisms and creep damage evolution characteristics at low stress with temperature ranging from 450 °C to 650 °C, in ...

Based on the dominated deformation mechanisms of superplastic materials, an assumption for micro-damage evolution is presented. Then, a set of uni®ed viscoplastic-damage constitutive equations is proposed to model material hardening due to the increase of dislocation density and grain growth, as well as material softening due to intergranular void nucleation and growth. The effects of the harde...

A recently developed crystal-mechanics-based constitutive model for polycrystalline shape-memory alloys (Thamburaja and Anand [1]) is shown to quantitatively predict the in-plane anisotropy of superelastic sheet Ti-Ni to reasonable accord. Keywords— Phase transformations, Constitutive equations, Finite-elements, Mechanical testing.

The present paper demonstrates that the Hart-Smith constitutive model and the more recent Arruda and Boyce eight chains and Gent constitutive models are closely related. The ability of these three models to predict both small and large strain responses of rubbers is highlighted and equations that relate their material parameters are established. INTRODUCTION Elastomers exhibit a very complex me...

in present study, thermo-elastic buckling analysis of multi-layer orthotropic annular/circular graphene sheets is investigated based on eringen’s theory. the moderately thick and also thick nano-plates are considered. using the non-local first and third order shear deformation theories, the governing equations are derived. the van der waals interaction between the layers is simulated for multi-...

In present study, thermo-elastic buckling analysis of multi-layer orthotropic annular/circular graphene sheets is investigated based on Eringen’s theory. The moderately thick and also thick nano-plates are considered. Using the non-local first and third order shear deformation theories, the governing equations are derived. The van der Waals interaction between the layers is simulated for multi-...

Based on a modified expression of the rate of the convective constraint release, we present a new contour-variable model of constitutive equations in which the non-uniform segmental stretch and the non-Gaussian chain statistical treatment of the single chain are considered to describe the polymer chain dynamics and the rheological behavior of an entangled system composed of linear polymer chain...

In this article, the problem of time-dependent stress redistribution of a piezomagnetic rotating thick-walled cylinder under an axisymmetric hygro-thermo-magneto-electro-mechanical loading is analyzed analytically for the condition of plane strain. Using the constitutive equations, a differential equation is found in which there are creep strains. Primarily, eliminating creep strains, an analyt...