scholarly journals Theoretical Study of Physico-mechanical Response of Permeable Fluid-Saturated Materials Under Complex Loading Based on the Hybrid Cellular Automaton Method

2020 ◽  
pp. 485-501
Author(s):  
Andrey V. Dimaki ◽  
Evgeny V. Shilko
Keyword(s):  
Cellular Automaton ◽  
Mechanical Response ◽  
Solid Phase ◽  
Fluid Pressure ◽  
Complex Loading ◽  
Theoretical Studies ◽  
Solid Skeleton ◽  
Theoretical Estimation ◽  
Liquid Phases ◽  
Cellular Automaton Method

AbstractWe give a brief description of the results obtained by Prof. Sergey G. Psakhie and his colleagues in the field of theoretical studies of mechanical response, including fracture, of permeable fluid-saturated materials. Such materials represent complex systems of interacting solid and liquid phases. Mechanical response of such a medium is determined by processes taking place in each phase as well as their interaction. This raised a need of developing a new theoretical approach of simulation of such media—the method of hybrid cellular automaton that allowed describing stress-strain fields in solid skeleton, transfer of a fluid in crack-pore volume and influence of fluid pressure on the stress state of the solid phase. The new method allowed theoretical estimation of strength of liquid-filled permeable geomaterials under complex loading conditions. Governing parameters controlling strength of samples under uniaxial loading and shear in confined conditions were identified.

scholarly journals Modelling of the Dendritic Crystallization by the Cellular Automaton Method

2016 ◽  
Vol 16 (1) ◽  
pp. 99-106 ◽  
Author(s):  
A. Zyska ◽  
Z. Konopka ◽  
M. Łągiewka ◽  
M. Nadolski
Keyword(s):  
Numerical Model ◽  
Cellular Automaton ◽  
Binary Alloy ◽  
Solid Phase ◽  
Dendritic Structure ◽  
Concentration Field ◽  
Surface Phenomena ◽  
Actual Structure ◽  
Dendritic Crystal ◽  
Cellular Automaton Method

Abstract A numerical model of binary alloy crystallization, based on the cellular automaton technique, is presented. The model allows to follow the crystallization front movement and to generate the images of evolution of the dendritic structures during the solidification of a binary alloy. The mathematic description of the model takes into account the proceeding thermal, diffusive, and surface phenomena. There are presented the results of numerical simulations concerning the multi-dendritic growth of solid phase along with the accompanying changes in the alloying element concentration field during the solidification of Al + 5% wt. Mg alloy. The model structure of the solidified casting was achieved and compared with the actual structure of a die casting. The dendrite interaction was studied with respect to its influence on the generation and growth of the primary and secondary dendrite arms and on the evolution of solute segregation both in the liquid and in the solid state during the crystallization of the examined alloy. The morphology of a single, free-growing dendritic crystal was also modelled. The performed investigations and analyses allowed to state e.g. that the developed numerical model correctly describes the actual evolution of the dendritic structure under the non-equilibrium conditions and provides for obtaining the qualitatively correct results of simulation of the crystallization process.

Heat capacities and enthalpies of fusion and transformation for solvates of some salts with dimethyl sulfoxide and dimethylformamide

1988 ◽  
Vol 53 (12) ◽  
pp. 3072-3079
Author(s):  
Mojmír Skokánek ◽  
Ivo Sláma
Keyword(s):  
Heat Capacity ◽  
Phase Transformation ◽  
Phase Transformations ◽  
Dimethyl Sulfoxide ◽  
Liquidus Temperature ◽  
Molar Heat Capacity ◽  
Solid Phase ◽  
Zinc Nitrate ◽  
Heat Capacities ◽  
Liquid Phases

Molar heat capacities and molar enthalpies of fusion of the solvates Zn(NO3)2 . 2·24 DMSO, Zn(NO3)2 . 8·11 DMSO, Zn(NO3)2 . 6 DMSO, NaNO3 . 2·85 DMSO, and AgNO3 . DMF, where DMSO is dimethyl sulfoxide and DMF is dimethylformamide, have been determined over the temperature range 240 to 400 K. Endothermic peaks found for the zinc nitrate solvates below the liquidus temperature have been ascribed to solid phase transformations. The molar enthalpies of the solid phase transformations are close to 5 kJ mol-1 for all zinc nitrate solvates investigated. The dependence of the molar heat capacity on the temperature outside the phase transformation region can be described by a linear equation for both the solid and liquid phases.

scholarly journals An Augmented Lagrangian Method for Sliding Contact of Soft Tissue

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Hongqiang Guo ◽  
Jeffrey C. Nickel ◽  
Laura R. Iwasaki ◽  
Robert L. Spilker
Keyword(s):  
Augmented Lagrangian ◽  
Soft Tissues ◽  
Augmented Lagrangian Method ◽  
Fluid Pressure ◽  
Complex Loading ◽  
Lagrangian Method ◽  
Sliding Contact ◽  
Element Formulation ◽  
Contact Interface ◽  
Diarthrodial Joints

Despite the importance of sliding contact in diarthrodial joints, only a limited number of studies have addressed this type of problem, with the result that the mechanical behavior of articular cartilage in daily life remains poorly understood. In this paper, a finite element formulation is developed for the sliding contact of biphasic soft tissues. The augmented Lagrangian method is used to enforce the continuity of contact traction and fluid pressure across the contact interface. The resulting method is implemented in the commercial software COMSOL Multiphysics. The accuracy of the new implementation is verified using an example problem of sliding contact between a rigid, impermeable indenter and a cartilage layer for which analytical solutions have been obtained. The new implementation’s capability to handle a complex loading regime is verified by modeling plowing tests of the temporomandibular joint (TMJ) disc.

Numerical Investigation of Ductile Fracture in Pipelines Under Complex Loading Using a Phenomenological Damage Model

2021 ◽  
Author(s):  
Iago S. Santos ◽  
Diego F. B. Sarzosa
Keyword(s):  
Ductile Fracture ◽  
Mechanical Response ◽  
Numerical Study ◽  
Damage Model ◽  
Stress Triaxiality ◽  
Numerical Procedure ◽  
Complex Loading ◽  
Experimental Tests ◽  
Compact Tension ◽  
Axial Tensile

Abstract This paper presents a numerical study on pipes ductile fracture mechanical response using a phenomenological computational damage model. The damage is controlled by an initiation criterion dependent on the stress triaxiality and the Lode angle parameter, and a post-initiation damage law to eliminate each finite element from the mesh. Experimental tests were carried out to calibrate the elastoplastic response, damage parameters and validate the FEM models. The tested geometries were round bars having smooth and notched cross-section, flat notched specimens under axial tensile loads, and fracture toughness tests in deeply cracked bending specimens SE(B) and compact tension samples C(T). The calibrated numerical procedure was applied to execute a parametric study in pipes with circumferential surface cracks subjected to tensile and internal pressure loads simultaneously. The effects of the variation of geometric parameters and the load applications on the pipes strain capacity were investigated. The influence of longitudinal misalignment between adjacent pipes was also investigated.

Supported imidazolium ionic liquid phases: A new material for solid-phase extraction

Talanta ◽  
2009 ◽  
Vol 80 (1) ◽  
pp. 250-256 ◽  
Author(s):  
Núria Fontanals ◽  
Sylwia Ronka ◽  
Francesc Borrull ◽  
Andrzej W. Trochimczuk ◽  
Rosa M. Marcé
Keyword(s):  
Ionic Liquid ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Phase Extraction ◽  
Imidazolium Ionic Liquid ◽  
Liquid Phases ◽  
New Material

scholarly journals Структура, зеренное строение и диэлектрические свойства керамик твердых растворов YCu-=SUB=-x-=/SUB=-Mn-=SUB=-1-x-=/SUB=-O-=SUB=-3-=/SUB=-

2021 ◽  
Vol 63 (3) ◽  
pp. 400
Author(s):  
А.В. Назаренко ◽  
А.В. Павленко ◽  
К.Г. Абдулвахидов
Keyword(s):  
Solid Phase ◽  
Hexagonal Phase ◽  
Anomalous Behavior ◽  
Ceramic Technology ◽  
Grain Structure ◽  
Dielectric Characteristics ◽  
Liquid Phases ◽  
Solid Phase Reactions ◽  
Interlayer Polarization ◽  
Isostructural Phase Transition

Solid solution ceramics of the YCuxMn1-xO3 system at x = 0.05; 0.10; 0.15 were prepared by solid-phase reactions followed by sintering using conventional ceramic technology. The study of their structure, microstructure and dielectric properties including of temperature and frequencies investigation of dielectric permittivity, conductivity and tangent of dielectric loses is carried out. It is established that hexagonal phase is predominantly formed in the ceramics. Its grain structure is unhomogenius, while synthesis is performed with the formation of liquid phases of eutectic origin. It is shown that anomalous behavior of dielectric characteristics at Т=30-200 ºС connected to interlayer polarization effects, while features at Т = 222 ºС (x = 0.05), 234 ºС (x = 0.10) and 247 ºС (x = 0.15) we connected to “isostructural” phase transition that is intermediate between the ferroelectric and paraelectric phases.

scholarly journals TOPOGRAPHIC CHANGES AROUND FENCE FOR PREVENTING WINDBLOWN SAND AND ITS PREDICTION USING CELLULAR AUTOMATON METHOD

2018 ◽  
Vol 74 (2) ◽  
pp. I_749-I_754
Author(s):  
Takuya YOKOTA ◽  
Akio KOBAYASHI ◽  
Takaaki UDA ◽  
Atsunari KATSUKI ◽  
Yasuhito NOSHI
Keyword(s):  
Cellular Automaton ◽  
Windblown Sand ◽  
Cellular Automaton Method
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