This study proposes a new comprehensive theoretical approach for predicting tensile stress-strain relation of Random Short Fiber Reinforced Cement Composites (RSFRCC) showing Pseudo Strain Hardening (PSH). This approach is grounded on solid basis of micromechanics, which describes PSH phenomenon in terms of constitutive properties of fiber, matrix, and fiber/matrix interface. The proposed model...

The effects of thermal elastic fluctuations in rubbery materials are examined. It is shown that, due to their interplay with the incompressibility constraint, these fluctuations qualitatively modify the large-deformation stress-strain relation, compared to that of classical rubber elasticity. To leading order, this mechanism provides a simple and generic explanation for the peak structure of Mo...

Extraction of the material stress-strain curve from a dynamic tensile or shear experiment is not straightforward. Indeed, stress and strain are not homogeneously distributed in the specimen, and consequently no one-one relation exists between the measured elongation and strain on one hand, and the measured force and stress on the other hand. This work aims at improving the accuracy of the stres...

In this paper, topology optimization of both geometrically and materially nonlinear structure is studied using a general displacement functional as the objective function. In order to consider large deformation, e2ective stress and strain are expressed in terms of 2nd Piolar–Kirchho2 stress tensor and Green–Lagrange strain tensor, and constitutive equation is derived from the relation between t...

The inverse energy cascade of two-dimensional (2D) turbulence is often represented phenomenologically by a Newtonian stress-strain relation with a ‘negative eddy-viscosity’. Here we develop a fundamental approach to a turbulent constitutive law for the 2D inverse cascade, based upon a convergent multi-scale gradient (MSG) expansion. To first order in gradients we find that the turbulent stress ...

in classical mechanics, considering hook’s law stress is a linear function of strain. while in strain gradient theory stress is a function of strain and strain differentials. in this paper, novel formulation relating stress and strain and also new boundary conditions are derived based on minimum potential energy principle. in strain gradient theory a length coefficient parameter is defined. thi...