Confining stress effect on the elastoplastic ground reaction considering the Lode angle dependence

Ancient sandstones include important reservoirs for hydrocarbons (oil and gas). This research provides an experimental investigation on the influence of variations in confining pressure on cementation factor of two wells located in Sirt basin. Measurements of formation resistivity factor versus cementation factor for sandstone samples which were collected from both wells at different confining pressures were carried out. The Effects of confining stress on the electrical properties of the rock samples were studied and analyzed. The results showed that the confining pressure variations depend on the pore structure of the studied rock. Furthermore, it can be concluded that the electrical resistivity of rocks is function of pore size distribution and how the fluids were distributed in the pore spaces. The effect of overburden pressure and the porosity variation on cementation factor is also investigated for different rock types. It has been concluded that the compaction due to overburden pressure generally causes a considerable increase in resistivity, especially in poorly cemented rocks. In low-porosity rocks, resistivity measurements determined under representative overburden pressures that are strongly recommended to improve well log interpretation.

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DEM exploration of confining stress effect in cyclic liquefaction of granular soils

Computers and Geotechnics ◽

10.1016/j.compgeo.2021.104214 ◽

2021 ◽

Vol 136 ◽

pp. 104214

Author(s):

Jiangtao Wei

Keyword(s):

Granular Soils ◽

Stress Effect ◽

Confining Stress

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Plasticity Model for Structural Steel with Lode Angle Dependence

Journal of Bridge Engineering ◽

10.1061/(asce)be.1943-5592.0001784 ◽

2021 ◽

Vol 26 (12) ◽

Author(s):

Yang Dong ◽

Liang-Jiu Jia

Keyword(s):

Structural Steel ◽

Plasticity Model ◽

Angle Dependence ◽

Lode Angle

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Localisation and Lode-Angle Dependence of Geomaterial Behaviour

Lecture Notes in Civil Engineering - ACMSM25 ◽

10.1007/978-981-13-7603-0_57 ◽

2019 ◽

pp. 581-590

Author(s):

L. A. Le ◽

G. D. Nguyen ◽

H. H. Bui ◽

A. H. Sheikh ◽

A. Kotousov

Keyword(s):

Angle Dependence ◽

Lode Angle

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Bent-Cap Confining Stress Effect on Slip of Prestressing Strands

ACI Structural Journal ◽

10.14359/51683868 ◽

2012 ◽

Vol 109 (4) ◽

Keyword(s):

Stress Effect ◽

Confining Stress ◽

Prestressing Strands

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Scattering-angle dependence of signal/background ratio of inner-shell electron excitation loss in EELS

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075701 ◽

1983 ◽

Vol 41 ◽

pp. 390-391

Author(s):

T. Oikawa ◽

M. Inoue ◽

T. Honda ◽

Y. Kokubo

Keyword(s):

Energy Loss ◽

Electron Excitation ◽

Heavy Elements ◽

Background Intensity ◽

Light Elements ◽

Energy Analyzer ◽

High Background ◽

Scattering Angle ◽

Angle Dependence ◽

Shell Electron

EELS allows us to make analysis of light elements such as hydrogen to heavy elements of microareas on the specimen. In energy loss spectra, however, elemental signals ride on a high background; therefore, the signal/background (S/B) ratio is very low in EELS. A technique which collects the center beam axial-symmetrically in the scattering angle is generally used to obtain high total intensity. However, the technique collects high background intensity together with elemental signals; therefore, the technique does not improve the S/B ratio. This report presents the experimental results of the S/B ratio measured as a function of the scattering angle and shows the possibility of the S/B ratio being improved in the high scattering angle range.Energy loss spectra have been measured using a JEM-200CX TEM with an energy analyzer ASEA3 at 200 kV.Fig.l shows a typical K-shell electron excitation edge riding on background in an energy loss spectrum.

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An Extension of Burzyński Hypothesis of Material Effort Accounting for the Third Invariant of Stress Tensor

Archives of Metallurgy and Materials ◽

10.2478/v10172-011-0054-4 ◽

2011 ◽

Vol 56 (2) ◽

pp. 503-508 ◽

Cited By ~ 11

Author(s):

R. Pęcherski ◽

P. Szeptyński ◽

M. Nowak

Keyword(s):

Stress Tensor ◽

Elastic Energy ◽

Yield Condition ◽

The Third ◽

Third Invariant ◽

Lode Angle

An Extension of Burzyński Hypothesis of Material Effort Accounting for the Third Invariant of Stress Tensor The aim of the paper is to propose an extension of the Burzyński hypothesis of material effort to account for the influence of the third invariant of stress tensor deviator. In the proposed formulation the contribution of the density of elastic energy of distortion in material effort is controlled by Lode angle. The resulted yield condition is analyzed and possible applications and comparison with the results known in the literature are discussed.

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