Temat: critical state - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Stress-dilatancy for soils. Part I: The frictional state theory
Autorzy:: Szypcio, Z.
Tematy:: soils
dilatancy
critical state
frictional state
critical frictional state; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/178347.pdf Link otwiera się w nowym oknie
Opis:: An unconventional subdivision of volumetric strains, the newly formulated frictional and critical frictional states and some of energetic and stress condition assumptions result in new stress-plastic dilatancy relationships. These new stress-plastic dilatancy relationships are functions of the deformation mode and drainage conditions. The critical frictional state presented in this paper is a special case of the classical critical state.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Stress-dilatancy relationship for railway balast
Autorzy:: Dołżyk-Szypcio, K.
Tematy:: railway ballast
critical state
frictional state
dilatancy; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/178215.pdf Link otwiera się w nowym oknie
Opis:: Knowledge of the mechanical behaviour of ballast is very important for designing a railway track, especially for high-speed lines. The monotonic drained triaxial tests of scaled and fouled ballast presented in literature were analysed using the Frictional State Theory. The stress-plastic dilatancy relationship shows that four characteristic stages of shearing may be specified. The influence of stress level and water content may be quantified by the use of the Frictional State Theory.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 3.

Tytuł:: Road transport systems safety criteria
Autorzy:: Bojar, P.
Woropay, M.
Tematy:: safety
intentional state boundary state critical state; Pokaż więcej
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Powiązania:: https://bibliotekanauki.pl/articles/246516.pdf Link otwiera się w nowym oknie
Opis:: Identification of boundary values and features which describe a system operation safety is a crucial problem for assessment of the system operation safety. In this article, an attempt to match features necessary for a description of a given system operation safety and determine their boundary values, has been made. Determination of boundary values of safety features will allow to evaluate the system safety level. The following variables have been accepted as safety features: the number of accidents, the number of fatalities, and the number of people injured in those accidents. According to these values, probability values of the numbers of people who were killed and who were injured in those accidents have been established. Probability value equal to zero has been accepted as the intentional state, the interval between 0 and the mean value of a given feature determines the acceptable state, the interval between the mean value of a given feature probability and value 0.1 determines the boundary state, whereas all features assuming values higher than 0.1 refer to the system critical state. The presented research results are considered as directives for development of safety criteria for road transport systems and determination of their critical values. The proposed method of boundary values determination can be used for assessment of safety for different transport systems.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 4.

Tytuł:: Stress-dilatancy for soils. Part IV: Experimental validation for simple shear conditions
Autorzy:: Szypcio, Z.
Tematy:: soils
dilatancy
critical state
frictional state
simple shear; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/178165.pdf Link otwiera się w nowym oknie
Opis:: This paper validates the frictional state theory using published experimental data from simple, direct and ring shear tests. Simple shear is treated as a special case of plane strain conditions. In order to define complete stress and strain, additional assumptions are made: in the direct shear and ring shear tests, simple shear is assumed to occur in the shear band. For Φ^° = Φ’_ϲϑ = Φ’_r, the stress-dilatancy relationship obtained from the frictional state theory is similar to the relationships proposed by Taylor and Bolton. Further experiments, especially those that use a hollow cylindrical shear apparatus, are necessary to fully validate the frictional state theory in simple shear conditions.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 5.

Tytuł:: Expansion of a cylindrical cavity in sand
Autorzy:: Osinov, V. A.
Cudmani, R.
Tematy:: cavity expansion
sand
hypoplasticity
critical state; Pokaż więcej
Wydawca:: Politechnika Gdańska
Powiązania:: https://bibliotekanauki.pl/articles/1954562.pdf Link otwiera się w nowym oknie
Opis:: The paper presents numerical solution to the problem of the symmetri quasi-static large-strain expansion of a cylindrical cavity in sand. The boundary value problem is solved with the use of a constitutive equation of hypoplasticity calibrated for a particular sand. As the radius of the cavity increases, the stresses and the density on the cavity surface asymptotically approach limit values which correspond to a so-called critical state of the sand. The limit values depend on the initial stresses and the initial density. The solutions are compared with experimental results for the same sand available in the literature. A comparison is also made with numerical solutions obtained by other authors.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 6.

Tytuł:: Time-dependant modelling of systems : some open questions
Autorzy:: Eid, M.
Tematy:: system
reliability
failure
critical state
transition
Boolean
graph; Pokaż więcej
Wydawca:: Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Powiązania:: https://bibliotekanauki.pl/articles/2069573.pdf Link otwiera się w nowym oknie
Opis:: Time dependent modelling of complex system is one of the important topics in system reliability engineering. Although system complexity is increasing, the existing models are numerically satisfactory. However, some formal development is still lacking in reliability theory. A full system time-dependency modelling and analysis is not possible without some formal answers on critical transitions and related issues. This is still one of the open questions in system reliability theory. Some promising development relative to critical states is given in this paper with an application case.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 7.

Tytuł:: Modelling of the pressure and density sensitive behaviour of sand within the framework of hypoplasticity
Autorzy:: Bauer, E.
Tematy:: hypoplasticity
element test
void ratio
critical state
granular materials; Pokaż więcej
Wydawca:: Politechnika Gdańska
Powiązania:: https://bibliotekanauki.pl/articles/1954566.pdf Link otwiera się w nowym oknie
Opis:: In this paper a hypoplastic model proposed by Gudehus and Bauer is presented which is apt to describe the mechanical behaviour of loose and dense sand within a wide range of pressures and densities using a single set of constants. State changes are assumed to depend on the current void ratio, the Cauchy stress tensor and the stretching tensor. The constitutive equation is of the rate type and based on non-linear tensor-valued functions. By including a pressure dependent relative density the hypoplastic model describes the influence of pressure and density on the incremental stiffness, the peak friction angle and on the void ratio in a stationary state. The performance of the hypoplastic models is discussed and the results of numerical simulations are compared with experiments.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 8.

Tytuł:: Maximization of Safety Lifetime of Critical Infrastructure Network with Cascading Effects Considering Climate-Weather Change Influence
Autorzy:: Blokus-Roszkowska, A.
Kołowrocki, K.
Tematy:: critical infrastructure
operation process
climate-weather change process
critical state
critical infrastructure safety lifetime maximization; Pokaż więcej
Wydawca:: Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Powiązania:: https://bibliotekanauki.pl/articles/2068749.pdf Link otwiera się w nowym oknie
Opis:: In the paper optimization of operation process and maximization of safety lifetimes for interconnected and interdependent critical infrastructure (CI) networks at variable operation conditions related to the climateweather change are proposed. A multistate series network with assets dependent according to local load sharing (LLS) rule is analyzed and optimization of operation and safety of CI network with the LLS rule is introduced. For such CI network, the optimal transient probabilities of CI network operation process at operation states related to climate-weather change that maximize the mean value of CI network safety lifetimes are found. Finally, the optimal safety and resilience indicators of CI network are presented.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 9.

Tytuł:: A comprehensive constitutive equation for granular materials
Autorzy:: Gudehus, G.
Tematy:: constitutive equation of soil
critical state
deformation
granular materials
stability analysis; Pokaż więcej
Wydawca:: Politechnika Gdańska
Powiązania:: https://bibliotekanauki.pl/articles/1954568.pdf Link otwiera się w nowym oknie
Opis:: constitutive equation is proposed for describing changes of states of granular materials, which are sufficiently characterised by the void ratio and the stress tensor. It may be considered as an extension of the Critical State concept. It is based on recently published hypoplastic equations and covers a wide range of densities, pressures and deformations. A factorial decomposition allows a rather easy separation and determination of material parameters. Two factors depend on a relative void ratio so that it remains within lower and upper bounds. The bounding void ratios decrease monotonously from maximal values to zero with increasing pressure. The same reduction of the void ratio is proposed for an isotropic compression starting from a suspension. Thus a granulate hardness is defined, and a stiffness factor can be determined. Four material parameters can be estimated from classification tests and determined from the asymptotic behaviour in element tests. Four further parameters are determined by calibration; they are rather constant for wide groups of materials. Strength and stiffness values can be derived and used for the analysis of deformations, stability, and flow. The viscous behaviour is modelled by a rate dependent factor with one further parameter. Limitations and possible extensions of this comprehensive approach are also outlined.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 10.

Tytuł:: Critical state constitutive models and shear loading of overconsolidated clays with deviatoric hardening
Autorzy:: Rachdi, Sara
Jahangir, Emad
Tijani, Michel
Serratrice, Jean-François
Tematy:: constitutive models
critical state
overconsolidated clay
shear loading
deviatoric hardening; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/178322.pdf Link otwiera się w nowym oknie
Opis:: This paper presents an enhanced constitutive model integrating deviatoric hardening with a modified yield surface for overconsolidated clayey soils in a general framework of Cam-clay type models. Its performance was assessed with the simulation of drained and undrained triaxial tests on three clays at different consolidation states in comparison to two critical state models. The proposed model satisfactorily estimates the shear resistance, while capturing the smooth nonlinearity of the soil response. Shear triaxial tests at constant mean pressure were performed on an overconsolidated marl to study the shear response. Their simulation attests the importance of deviatoric hardening integration.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Informacja

Wyszukujesz frazę "critical state" wg kryterium: Temat