Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "shear" wg kryterium: Wszystkie pola


Wyświetlanie 1-10 z 10
Tytuł:
Numerical studies on patterning of shear zone in granular bodies
Autorzy:
Tejchman, J.
Powiązania:
https://bibliotekanauki.pl/articles/1954556.pdf
Data publikacji:
2000
Wydawca:
Politechnika Gdańska
Tematy:
localisation
hypoplasticity
polar continuum
boundary conditions
shear zone
finite element method
Opis:
The paper deals with numerical investigations on the patterning of shear zones in granular bodies. The behaviour of dry sand during plane strain compression tests was numerically modelled with a finite element method using a hypoplastic constitutive relation within a polar (Cosserat) continuum. The constitutive relation was obtained through an extension of a non-polar one by polar quantities, viz. rotations, curvatures, couple stresses using the mean grain diameter as a characteristic length. This relation can reproduce the essential features of granular bodies during shear localisation. The material constants can be easily determined from element test results and can be estimated from granulometric properties. The attention is laid on the influence of boundary conditions and the distribution of imperfections in the granular specimen on the formation of patterns of shear zones.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2000, 4, 3; 485-516
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of heterogeneity on shear zone formation during plane strain compression
Autorzy:
Tejchman, J.
Powiązania:
https://bibliotekanauki.pl/articles/241506.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
heterogeneity
mean grain diameter
polar continuum
shear zone
void ratio
Opis:
Heterogeneity of granular materials triggers shear zone formation. In the paper, the FE-analysis of the effect of the material heterogeneity on the formation of a spontaneous shear zone inside of granular materials during a plane strain compression test is presented. The numerical calculations are performed with a finite element method on the basis of a hypoplastic constitutive law extended by polar quantities: rotations, curvatures and couple stresses. A mean grain diameter is used as a characteristic length. The constitutive law takes into account the effect of pressure, void ratio, direction of deformation rate and mean grain diameter on the behaviour of granular bodies. The heterogeneity in the granular body is assumed in the form of spots with a different initial void ratio. The spots are single or distributed randomly and stochastically with an exponential probability function. The single spots are distributed sparsely and densely in an initially dense and loose granular specimen. Special attention is focused on the effect of heterogeneity on the onset of shear localization and its thickness at residual state.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2004, 51, 2; 149-181
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of shear localization in granular bodies within gradient-enhanced hypoplasticity
Autorzy:
Tejchman, J.
Powiązania:
https://bibliotekanauki.pl/articles/241309.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
characteristic length
finite element method
gradient model
plane strain compression
shear localization
Opis:
The paper presents a FE-analysis of a spontaneous shear localization inside non-cohesive sand during plane strain compression. The calculations were carried out with a gradient-enhanced hypoplastic constitutive law. The hypoplastic law can reproduce essential features of granular bodies depending on the void ratio, pressure level and deformation direction. To model the thickness of shear zones, a characteristic length of the microstructure was incorporated via the second gradient of the modulus of the deformation rate. To determine the effect of micro-structure, the analysis was performed with different characteristic lengths for the same specimen size.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2004, 51, 3; 243-265
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations of shear localization in granular bodies within an anisotropic micro-polar hypoplasticity
Autorzy:
Tejchman, J.
Powiązania:
https://bibliotekanauki.pl/articles/241368.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
bedding plane
granular materials
hypoplasticity
micropolar theory
shear zone
texturial anisotropy
Opis:
The paper focuses on the numerical analysis of the effect of texturial anisotropy on shear localization in cohesionless granular materials. For simulation of the mechanical behaviour of a granular material during a monotonous deformation path, a hypoplastic constitutive model was used. To take into account a characteristic length of micro-structure, the constitutive model was extended by micro-polar terms. To take into account texturial effects, the granular hardness was modified. The calculations were carried out with a sand specimen during plane strain compression under constant lateral pressure. A stochastic and uniform distribution of the initial void ratio in the granular specimen was assumed. In addition, shear localization for two different uniform initial void ratios was investigated.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2005, 52, 4; 351-371
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Non-local hypoplastic constitutive law to describe shear localisation in granular bodies
Autorzy:
Tejchman, J.
Powiązania:
https://bibliotekanauki.pl/articles/240962.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
characteristic length
finite element method
non-local model
plane strain compression
shear localization
Opis:
The paper presents a FE-analysis of shear localisation in granular bodies by a finite element method based on a hypoplastic constitutive law. The law can reproduce essential features of granular bodies depending on the void ratio, pressure level and deformation direction. To realistically simulate the formation of a spontaneous shear zone inside cohesionless sand during plane strain compression, a hypoplastic constitutive law was extended by non-local terms. The effects of initial void ratio, pressure level and a characteristic length on the thickness of an interior shear zone were shown. The numerical results were compared with corresponding laboratory tests.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2003, 50, 4; 359-379
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evolution of shear localisation in earth pressure problems of a retaining wall
Autorzy:
Tejchman, J.
Powiązania:
https://bibliotekanauki.pl/articles/1986988.pdf
Data publikacji:
2002
Wydawca:
Politechnika Gdańska
Tematy:
earth pressure
granular materials
finite element method
hypoplasticity
polar continuum
retaining wall
shear localization
Opis:
The paper deals with numerical investigations of the evolution of shear localisation in granular bodies for earth pressure problems of a retaining wall in conditions of plane strain. The passive and active failure of a retaining wall in sand is discussed. The calculations are carried out with a rigid and very rough retaining wall undergoing horizontal translation, rotation around the top and rotation around the bottom. The behaviour of dry sand is numerically modelled with a finite element method using a hypoplastic constitutive relation within a polar (Cosserat) continuum. The constitutive relation is obtained through extension by polar quantities, viz. rotations, curvatures and couple stresses, using the mean grain diameter as a characteristic length. During FE-calculations, the attention is laid on the influence of different wall movements on shear localisation. In addition, the effects of the initial void ratio, distribution of the initial void ratio and mean grain diameter, pressure level and size of the sand body and retaining wall is investigated in the case of a passive wall translation. The FE-results are compared with corresponding experimental results of laboratory model tests.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2002, 6, 3; 387-410
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stochastic FE-analysis of shear localization in 2D granular material within a micro-polar hypoplasticity
Autorzy:
Tejchman, J.
Górski, J.
Powiązania:
https://bibliotekanauki.pl/articles/241120.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
granular materials
micro-polar hypoplasticity
shear localization
correlated random field
void ratio
Opis:
The paper deals with investigations of the effect of the stochastic distribution of the initial void ratio in granular bodies on shear localization during shearing of an infinite granular layer 500 mm high with free dilatancy under plane strain conditions. The initial void ratio was assumed to be stochastic with a correlated random field generated by a conditional rejection method by Walukiewicz et al (1997). To simulate mechanical behaviour of a cohesionless granular material during a monotonous deformation path, a micro-polar hypoplastic constitutive law was used, which takes into account particle rotations, curvatures, non-symmetric stresses, couple stresses and the mean grain diameter as a characteristic length. The proposed model captures the salient mechanical features of granular bodies in a wide range of densities and pressures with a single set of constants. In addition, the comparative FE-analyses were carried out with a uniform and spatially non-correlated random fields of the initial void ratio.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2006, 53, 4; 353-379
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fe-analysis of patterning of shear zones in granular bodies for earth pressure problems of a retaining wall
Autorzy:
Tejchman, J.
Powiązania:
https://bibliotekanauki.pl/articles/241166.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
earth pressure
granular materials
finite element method
hypoplasticity
polar continuum
retaining wall
shear localization
Opis:
The evolution of shear zones in granular bodies for earth pressure problems of a retaining wall in conditions of plane strain was analyzed. The passive and active failure of a retaining wall was discussed. The calculations were carried out with a rigid and very rough retaining wall undergoing horizontal translation, rotation around the top and rotation around the bottom. The behaviour of dry sand was numerically modelled with a finite element method using a hypoplastic constitutive relation with polar extensions. Attention was paid to the influence of different wall movements on shear localization. The initial void ratio was assumed to be non-uniformly distributed. The geometry of calculated shear zones was compared with corresponding experimental results of laboratory model tests.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2004, 51, 4; 317-348
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Grain Crushing on Shear Localization in Granular Bodies within Micro-Polar Hypoplasticity
Autorzy:
Tejchman, J.
Powiązania:
https://bibliotekanauki.pl/articles/241516.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
breakage mechanics
grain crushing
micro-polar hypoplasticity
sand
shearing
Opis:
The paper deals with the effect of grain crushing on shear localization in granular materials in an infinite long narrow granular strip under constant vertical pressure. The calculations were carried out with an enhanced micro-polar hypoplastic constitutive model which is able to describe the salient properties of crushable granular bodies including shear localization. The change of the mean grain diameter with varying pressure was taken into account with the help of formulae from breakage mechanics. The effect of pressure and initial void ratio on shear localization was studied.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2010, 57, 1; 3-30
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Size Effects in Problems of Footings on Sand within Micro-Polar Hypoplasticity
Autorzy:
Tejchman, J.
Górski, J.
Powiązania:
https://bibliotekanauki.pl/articles/241079.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
footing
micro-polar hypoplasticity
sand
shear localization
size effect
stratified sampling
void ratio
Opis:
Numerical FE investigations of size effects in problems of footings on sand were performed. Micro-polar hypoplastic constitutive model was used to describe a mechanical behaviour of a cohesionless granular material during a monotonic deformation path. The FE analyses were carried out with three different footing widths. In deterministic calculations, a uniform distribution of initial void ratio was used. In statistical calculations, initial void ratios took the form of random spatial fields described by a truncated Gaussian random distribution. In order to reduce the number of stochastic realizations without sacrificing the accuracy of the calculations, a stratified sampling method was applied. The numerical results were compared with corresponding laboratory tests by Tatsuoka et al (1997). The numerical results show that the bearing capacity of footings decreases with increasing specimen size. If the initial void ratio is stochastically distributed, the mean bearing capacity of footings may be larger than the deterministic value. The statistical size effect is smaller than the deterministic one.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2008, 55, 3-4; 95-124
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies