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Przegląd wybranych rozwiązań teoretycznych jednoosiowej konsolidacji gruntów

Olek B. S.

Przegląd Geologiczny

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2018

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Vol. 66, nr 5

309--320

EN

This paper presents the review on available approaches to predicting consolidation settlement of cohesive soils. The progress of deformation in clays is visualized as the combination of hydrodynamic and rheological processes. The first part deals with infinitesimal consolidation theories. The second part is a review of finite strain solutions that describe consolidation of soils. Non-linear one-dimensional consolidation of a thin and thick clay deposit considering linear void ratiolog effective stress relationship, self-weight of soil, constant volume (1+void ratio), thickness of clay layer and coefficient of consolidation also were considered. This aspects was illustrated for different cases on the basis of variations of degree of consolidation obtained both for settlements and dissipation of excess pore water pressures. In addition attention was paid to non-linearity ofpermeability and compressibility during consolidation course, variablity of coefficient of consolidation and time-dependent soil response.

2

Modelling and simulation of the curing process of polymers by a modified formulation of the Arruda–Boyce model

Hossain M., Steinmann P.

Archives of Mechanics

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2011

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Vol. 63, nr 5-6

621-621

EN

A phenomenologically motivated small strain model and a finite strain general framework to simulate the curing process of polymer have been developed and discussed in our recently published papers [1, 2, 3, 4]. In order to illustrate the capability of the finite strain framework proposed earlier, only the micromechanically-inspired 21-chain model and the phenomenologically motivated Neo-Hookean model (energy function) have been demonstrated so far. The Arruda–Boyce model (well-known as the 8-chain model in the elastic case and Bergström–Boyce model [5, 14] in the viscoelastic case) is a prototype hyperelastic model for polymeric materials. This follow-up contribution presents an extension of the Arruda–Boyce model [6] towards modelling the curing process of polymers. The necessary details, i.e. the stress tensor and the tangent operator, for the numerical implementation within the finite element method, are derived. The curing process of polymers is a complicated process where a series of chemical reactions have been activated, which will convert low molecular weight monomer solutions into more or less cross-linked solid macromolecular structures via the chemical conversion. This paper will model the elastic behaviour and shrinkage effects of the polymer curing process in the isothermal case using the Arruda–Boyce model. Several numerical examples have been demonstrated to verify our newly proposed, modified approach in case of curing process.

3

Biaxial extension of a plane single crystal

Merabet K., Chenaoui A., Sidoroff F., Darrieulat M.

Archives of Mechanics

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2008

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Vol. 60, nr 5

363-384

EN

This paper concerns the rigid-plastic modelisation of a f.c.c. single crystal, deforming by crystallographic slip, under large strain. Adopting the plane single crystal model, which corresponds to a true two-dimensional evolution of a real three-dimensional crystal, the activity of slip systems and the plastic indetermination, due to multiplicity of solutions, are studied according to the rate-independent Schmid law or the rate-dependent Bingham law. To promote a more general situation of potential multiple slip and therefore of potential indeterminacy, the biaxial loading is investigated. Based on this model and the Bingham slip law, the indeterminacy problem is surmounted, by adopting the geometrical analysis in the strain rate space and it is proved that the linear viscoplastic analysis is a new way of solving the indeterminacy problem.

4

A multi-scale "morphological approach" for highly-filled participate composites: evaluation in hyperelasticity and first application to viscohyperelasticity

Touboul M., Nadot-Martin C., Dragon A., Fanget A.

Archives of Mechanics

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2007

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Vol. 59, nr 4-5

403-433

EN

This article deals with a non-classical scale transition devoted, in the long-run, to the prediction of the nonlinear mechanical behavior of energetic composites. A geometrical and kinematical schematization of the microstructure is defined as a conspicuous starting point for further localization-homogenization procedure. Thus, salient information on the morphology and some intraphase heterogeneity are taken into account. The first results obtained in a finite strain context for a three-dimensional periodic microstructure are compared to the finite element solution. Furthermore, the ability of the methodology to deal with viscohyperelasticity in a direct manner is illustrated. This is a significant step towards efficient mastery of the scale transition for viscoelastic aggregates, whose inherent characteristic lies in space/time local interactions and relative "long-memory" effect.

5

The plane single crystal under off-axis uniaxial tension

Chenaoui A., Sidoroff F., Darrieulat M., Hihi A.

Archives of Mechanics

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2002

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Vol. 54, nr 3

223-244

EN

The tensile behaviour of a rigid-plastic single crystal obeying Schmid's law with isotropic hardening is investigated for an off-axis tensile test in one of its symmetry planes (plane single crystal). Identification of the active slip systems allows the determination of the plastic spin and the resulting evolution of the crystallographic directions. This results in the description of the tensile behaviour-stress and strain response, onset of instability - depending upon the initial orientation of the crystal and the hardening law.