Yes (80)
Used filters
(4)
Number of found documents:
80
Published from
to
Implicit constitutive solution scheme for Mohr-Coulomb plasticity
Sysala, Stanislav; Čermák, M.
2017 - English
This contribution summarizes an implicit constitutive solution\nscheme of the elastoplastic problem containing the Mohr-Coulomb yield cri-\nterion, a nonassociative \now rule, and a nonlinear isotropic hardening. The\npresented scheme builds upon the subdifferential formulation of the \now rule\nleading to several improvements. Mainly, it is possible to detect a position\nof the unknown stress tensor on the Mohr-Coulomb pyramid without blind\nguesswork. Further, a simplifed construction of the consistent tangent opera-\ntor is introduced. The presented results are important for an efficient solution\nof incremental boundary value elastoplastic problems.
Keywords:
Mohr-Coulomb plasticity; implicit constitutive solution scheme; consistent tangent operator
Fulltext is available at external website.
Implicit constitutive solution scheme for Mohr-Coulomb plasticity
This contribution summarizes an implicit constitutive solution\nscheme of the elastoplastic problem containing the Mohr-Coulomb yield cri-\nterion, a nonassociative \now rule, and a nonlinear ...
Overlapping domain decomposition preconditioners for elliptic and parabolic problems in primal and mixed form
Blaheta, Radim
2017 - English
In this lecture, we concern the numerical solution of PDE problems and describe overlapping domain decomposition, which provides a tool for the construction of parallelizable Schwarz type iterative solvers and preconditioners. The idea of using overlapping domain decomposition goes back to Schwarz alternating method from 1870, see [1]. The analysis of this alternating iterative method was evolved by great mathematicians, see e.g. S.L. Sobolev (1936), R. Courant and D. Hilbert (1937), S.G. Michlin (1951), M. Práger (1958), I. Babuška (1958), F.E. Browder (1958). The use of overlapping domain decomposition for parallel computations started in the late eighties in the work of M. Dryja and O. Widlund [4], P.L. Lions [5, 6], S. Nepomnyaschikh [7] and others and continue up to the present days. The origin of the alternating Schwarz method is nicely described in [8].
Keywords:
preconditioners; Schwarz method; matrix Ma
Fulltext is available at external website.
Overlapping domain decomposition preconditioners for elliptic and parabolic problems in primal and mixed form
In this lecture, we concern the numerical solution of PDE problems and describe overlapping domain decomposition, which provides a tool for the construction of parallelizable Schwarz type iterative ...
Algebraic preconditioning for Biot-Barenblatt poroelastic systems
Blaheta, Radim; Luber, Tomáš
2017 - English
Poroelastic systems describe fluid flow through porous medium coupled with deformation of the porous matrix. In this paper, the deformation is described by linear elasticity, the fluid flow is modelled as Darcy flow. The main focus is on the Biot-Barenblatt model with double porosity/double permeability flow, which distinguishes flow in two regions considered as continua. The main goal is in proposing block diagonal preconditionings to systems arising from the discretization of the Biot-Barenblatt model by a mixed finite element method in space and implicit Euler method in time and estimating the condition number for such preconditioning. The investigation of preconditioning includes its dependence on material coefficients and parameters of discretization.
Keywords:
poroelasticity; double permeability; preconditioning; Schur complement
Fulltext is available at external website.
Algebraic preconditioning for Biot-Barenblatt poroelastic systems
Poroelastic systems describe fluid flow through porous medium coupled with deformation of the porous matrix. In this paper, the deformation is described by linear elasticity, the fluid flow is ...
Dynamization of spatial data using location-based services: Tourist potential of industrial heritage
Malý, Jiří; Krejčí, Tomáš; Trojan, Jakub; Chudáček, Stanislav; Nováková, Eva
2017 - English
The paper deals with industrial heritage and its potential in tourism. Although the post-industrial landscape is an integral part of all the countries that went through a period of de-industrialization and economic transformation, presentation and publicity of valuable industrial monuments that are linked with post-industrial landscape in many cases are not fully utilized. This paper aims to acquaint readers with a possibility of transformation of data on industrial objects into augmented reality, while using location-based services. The final result is the web-based platform allowing easy data transformation. The paper has thus largely methodological-application character. The outcomes of the testing phase indicate that information about the objects do have their limits, but respecting them brings their effective performance in augmented reality.
Keywords:
location-based services; augmented reality; industrial heritage; tourism; Czech Republic
Available in a digital repository NRGL
Dynamization of spatial data using location-based services: Tourist potential of industrial heritage
The paper deals with industrial heritage and its potential in tourism. Although the post-industrial landscape is an integral part of all the countries that went through a period of ...
Local geoheritage: its importance and potential for geotourist and recreational activities (a case study from Lomnicko area)
Kirchner, Karel; Kubalíková, Lucie; Bajer, A.
2017 - English
Geodiversity, respectively its valuable part – geoheritage is considered an important resource for the geotourism and recreation purposes. In the C.R., there are a lot of examples of such use of geoheritage: sandstone rock cities, karst areas or polygenetic relief at mountain areas and others. These geoheritage features are usually significant on the national level, their existence assure the attractiveness of the given area, enables the geotourist and recreational activities and support the local and regional development. However, in the local scale, the geodiversity (respectively geoheritage, represented by particular geosites and geomorphosites) can also serve the above mentioned purposes. The paper presents the example from Lomnicko area which can be seen as an “average” area from the geodiversity/geoheritage point of view on the national level, but on the local and regional level, there is a considerable number of geosites and geomorphosites with a potential for geotourism and recreation.
Keywords:
geodiversity; geosite; geomorphosite; geotourism
Available in a digital repository NRGL
Local geoheritage: its importance and potential for geotourist and recreational activities (a case study from Lomnicko area)
Geodiversity, respectively its valuable part – geoheritage is considered an important resource for the geotourism and recreation purposes. In the C.R., there are a lot of examples of such use of ...
Bifurcations in contact problems with Coulomb friction
Ligurský, Tomáš; Renard, Y.
2017 - English
To explore the bifurcation in this contact problem, we have taken uniform meshes with 4096, 16384, 65536 and 262144 triangles. We shall show that the bifurcation behaviour is more complex here. Branches 1 and 4 approach one another for finer meshes, and they disappear both for the finest mesh. Nevertheless, regarding the branching of the corresponding contact problem with forces h = (h1,h2) over the plane h1-h2, one can find it stable and convergent, again. \n
Keywords:
bifurcation; contact problem; Coulomb friction
Fulltext is available at external website.
Bifurcations in contact problems with Coulomb friction
To explore the bifurcation in this contact problem, we have taken uniform meshes with 4096, 16384, 65536 and 262144 triangles. We shall show that the bifurcation behaviour is more complex here. ...
Large-scale geosimulations using GEM and trilions
Blaheta, Radim; Jakl, Ondřej; Hrtus, Rostislav; Kolcun, Alexej; Kohut, Roman; Starý, Jiří; Turan, E.
2017 - English
The project deals with efficient solution of singular symmetric positive semidefinite problems. Our motivation arises from the \nneed to solve special problems of geotechnics, e.g. to perform upscaling analysis of geocomposites. In that and other applications we have to solve boundary problems with pure Neumann boundary conditions. We show that the stabilised PCG method with various preconditioners is a good choice for systems resulting from the numerical solution of Neumann problems, or more generally problems with a known small dimensional null space. The work was also taken as an opportunity to compare parallel implementations of the orresponding solvers, namely implementations in the in-house finite element software GEM and implementations employing components of the general Trilinos library. The studies show that the solvers based on GEM are highly competitive with its recognised counterpart.
Keywords:
singular symmetric positive semidefinite problems; special problems of geotechnics; PCG method
Fulltext is available at external website.
Large-scale geosimulations using GEM and trilions
The project deals with efficient solution of singular symmetric positive semidefinite problems. Our motivation arises from the \nneed to solve special problems of geotechnics, e.g. to ...
Professor Ivo Marek (1933-2017)
Blaheta, Radim; Tůma, Miroslav
2017 - English
Ivo Marek, Professor at Charles University and the Czech Tec\nhnical University in Prague, was for many decades one of the best-known Czech ma\nthematicians, who contributed significantly to the development of computa\ntional methods and numerical analysis. At the same time, he was a teacher and a le\nading personality that integrated and influenced the Czech mathematical commu\nnity.
Fulltext is available at external website.
Professor Ivo Marek (1933-2017)
Ivo Marek, Professor at Charles University and the Czech Tec\nhnical University in Prague, was for many decades one of the best-known Czech ma\nthematicians, who contributed significantly to the ...
The GIS support to measures on the ground in case of leakage of liquid pollutant on the road
Kolejka, Jaromír; Rapant, P.; Zapletalová, Jana
2016 - English
Accidents on roads associated with the leakage of hazardous substances are one of the major challenges encountered by disaster management. Because of the impossibility of predicting the place and time of the event, then it is necessary in the event of such an accident to proceed in quick succession of steps. They are designed primarily to protect human life and health, and then to minimize to property and environment damage. The paper describes the response to this event using GIS tools and generally available geodata. The simulated accident on the D1 highway near Ostrava is applied as a demonstration example.
Keywords:
GIS decision support; geographic data and knowledge; geography
Available in digital repository of the ASCR
The GIS support to measures on the ground in case of leakage of liquid pollutant on the road
Accidents on roads associated with the leakage of hazardous substances are one of the major challenges encountered by disaster management. Because of the impossibility of predicting the place and time ...
Geodiversity values as a basis for geosite and geomorphosite assessment: a case study from Žďárské vrchy Highland
Bajer, A.; Kirchner, Karel; Kubalíková, L.
2016 - English
Paper presents geodiversity values, geodiversity is understood as a set of geological, geomorphological and pedological components, including systems consisting of this components and geological, geomorphological and pedological processes. Geodiversity values are analyzed in relation to ecosystem values (e.g. cultural, functional value). Geodiversity values were used as basis for a methodical approach to geosite and geomorphosite assessment. Methodological approach is presented at selected sites in the top part of the Žďárské vrchy Highland. The acquired results can serve as a basis for geoconservation of PLA Žďárské vrchy, development of geotourism as well as an offer for extension geoeducational activities.\n
Keywords:
geodiversity; geoeducation; geosite; geomorphosite assessment
Available in digital repository of the ASCR
Geodiversity values as a basis for geosite and geomorphosite assessment: a case study from Žďárské vrchy Highland
Paper presents geodiversity values, geodiversity is understood as a set of geological, geomorphological and pedological components, including systems consisting of this components and geological, ...
NRGL provides central access to information on grey literature produced in the Czech Republic in the fields of science, research and education. You can find more information about grey literature and NRGL at service web
Send your suggestions and comments to nusl@techlib.cz
Provider
Other bases