No abstract available

[en] In an attempt to correct the unrealistic material stiffness predicted by elastoplastic models which adopt an associative flow rule, this paper introduces an innovative technique for the computation of the inelastic contributions generated in a non-proportional loading path. The formulation of these inelastic contributions takes into account the plastic response along the direction normal to the plastic potential, neglecting the irreversible stretch caused by the tangential component of the stress rate. Here, the introduction of tangential plasticity, in combination with the return mapping technique, eliminates this drawback, allowing fast and accurate computation. The present paper focuses on the evaluation of the load-carrying capacity of a steel bridge pier, indicating the necessity of considering the additional tangential plasticity term for a correct description of the structural response.

No abstract available

[en] The seismic performances of R.C. frame structures were determined in terms of inter-storey drifts at two limit states, internal forces and moments (axial forces and bending moments), and the in-plane behaviour of infills. A nonlinear static analysis (pushover) was carried out in order to assess the seismic performance of buildings, to identify the expected plastic mechanisms and to plot the capacity curves. In pushover analysis, the vertical distribution of the monotonically increasing horizontal loads, was performed according to the first mode pattern. The nonlinear behaviour of structural members for pushover analysis was modelled by using the lumped plasticity, from where it derives that the potential plastic hinges were situated at the beams ends (which yield due to the bending moment), at the top and bottom of the columns at any storey (which yield based on the interaction of axial force and bending moment) and in the struts (which yield due to the axial force). (paper)

[en] We propose an elasto-plastic model coupled with damage for the behavior of geomaterials in compression. The model is based on the properties, shown in S. Andrieux, et al., 'Un modele de materiau microfissure pour les betons et les roches', J. Mecanique Theorique Appliquee 5 (1986) 471-513, of microcracked materials when the microcracks are closed with a friction between their lips. That leads to a macroscopic model coupling damage and plasticity where the plasticity yield criterion is of the Drucker-Prager type with kinematical hardening. Adopting an associative flow rule for the plasticity and a standard energetic criterion for damage, the properties of such a model are illustrated in a triaxial test with a fixed confining pressure. (authors)

No abstract available

[en] Short communication

[en] Two types of Large Area Plastic Scintillator Detector with different size and model were described. The basic construction and working process was introduced. A Characteristics contrasting was made between the two types of Large Area Plastic Scintillator Detectors. The technology designing of the whole detector components was also described here. (authors)

[en] Thin isotropic rotation shells of constant thickness taking into account the appearance of plastic deformations under the local loads are considered. The method of running with discrete orthogonalization is used for the numerical realisation of the present problem. Thin spherical shells with the angle 90 degrees and the relation of the radius to the thickness 100 under local load are considered. (paper)

[en] A new invariant of stress tensor is introduced - the mean shearing stress, resulted from the integration with respect to Mohr's circle. The invariant is used to lay down the terms of plasticity. Determining equations are written on the basis of associated flow law. Rigid variants of the model and elastoplastic ones are obtained. Characteristic surfaces with normals, coinciding with main stresses direction are demonstrated for the rigid-plastic variant. (paper)