The stress integration procedure proposed by Eterovic and Bathe [Inr. J. numer. Merh. Engng 30, 1099-l 114 (1990).] is studied in detail. The elasto-plasticity formulation is based on the use of the total logarithmic strains and Cauchy stresses, and the Euler backward method of time integration. The accuracy of the procedure is assessed in the solution of various analysis problems and is compar...

This paper presents an overview of elasto-plastic modelling of unsaturated soils. Alternative stress and strain variables that have been used in constitutive models for unsaturated soils are discussed. The use of an effective stress equation may simplify constitutive relations, but often result in a stress space that depends on the material state. In this case, the constitutive behaviour is emb...

In this study, tensile loading experiments are performed on notched steel bars at an average applied strain rate of 1s. Displacement fields are measured across the specimen by coupling digital image correlation (DIC) with imaging using high speed CCD cameras (4796 fps). Results from the experiments indicate the presence of local strain rates ranging from 0.1 to 10s in the notched specimens. The...

−βθ div ut , has been derived and existence of global strong solutions in 3D for the isothermal case has been proved in [1]. Existence for the full system under suitable hypotheses is proved in [2]. The unknowns are u (displacement of the solid matrix), p (capillary pressure), and θ (absolute temperature). The system contains four hysteresis operators: The degenerate Preisach operator G describ...

This paper presents a criterion for detecting diffuse (homogeneous) instabilities in granular soils sheared under fully drained conditions. The criterion is based on bifurcation theory and applied to elasto-plasticity by allowing multiple incremental solutions in elasto-plastic soils, physically losing controllability of stress boundary conditions. Drained diffuse instabilities are poorly under...

The orthogonal processes to shape the triangle steel plate into a equilateral vertical steel are examined by an incremental elasto-plastic finite-element method based on an updated Lagrangian formulation. The highly non-linear problems due to the geometric changes, the inelastic constitutive behavior and the boundary conditions varied with deformation are taken into account in an incremental ma...

This paper proposes a new approach for representing elasto-plastic behavior through graphical visualization of the yield surface and the stress path in the principal stress space. The yield surface is defined by thematerial parameters of a given yield criterion, and the stress path is formed by a number of stress points, each of which is obtained for every increment in the applied force. The su...

This study is devoted towards evaluating seismic performance of a three-span continuous highway bridge subjected to moderate to strong earthquake ground motions in its longitudinal direction. In this regard, nonlinear dynamic analysis of the bridge based on the direct time integration approach using the 4 order Runge-Kutta method is conducted. Two types of isolation bearings are used in the ana...