A model for irreversible deformation phenomena driven by hydrostatic stress, deviatoric stress and an externally applied field

Stress invariants approach to the multiaxial fatigue life estimation is generally based on the root mean square value of second invariant of the deviatoric stress amplitude and the value of hydrostatic stress. Such an approach omits a significant part of the information about multiaxial load history. It is particularly noticeable in case of non-proportional loadings, which lead to a reduction of fatigue life (i.e. [1–3]). In this work a new method based on the mean value of modified second invariant of the deviatoric stress has been presented.

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3 Dimensional Microscopical Pore Distribution of Kimachi Sandstone and Its Permeability and Specific Storage Change by Hydrostatic Stress and Deviatoric Stress

Journal of the Japan Society of Engineering Geology ◽

10.5110/jjseg.53.31 ◽

2012 ◽

Vol 53 (1) ◽

pp. 31-42 ◽

Cited By ~ 2

Author(s):

Manabu TAKAHASHI ◽

Masaji KATO ◽

Naoki TAKAHASHI ◽

Yukiyasu FUJII ◽

Hyuck PARK ◽

...

Keyword(s):

Hydrostatic Stress ◽

Deviatoric Stress ◽

Pore Distribution ◽

Specific Storage ◽

3 Dimensional ◽

Storage Change

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Crystal Structure of Urotropine Under High Pressure and Non-Hydrostatic Stress-Induced Phase Transitions in Cage Compounds

10.26434/chemrxiv.12103233.v1 ◽

2020 ◽

Author(s):

Piotr A. Guńka ◽

Anna Olejniczak ◽

Samuele Fanetti ◽

Roberto Bini ◽

Ines E. Collings ◽

...

Keyword(s):

Crystal Structure ◽

Phase Transition ◽

High Pressure ◽

Structural Changes ◽

Hydrostatic Stress ◽

Atomic Displacement ◽

Deviatoric Stress ◽

Cage Compounds ◽

First Order Phase Transition ◽

Atomic Displacement Parameters

High-pressure behavior of hexamthyleneteramine (urotropine) was studied in situ using angle-dispersive single-crystal synchrotron X-ray diffraction (XRD) and Fourier transform infrared absorption (FTIR) spectroscopy. Experiments were conducted in various pressure transmitting media (helium and neon for XRD, nitrogen and KBr for FTIR experiments) to study the effect of deviatoric stress on phase transformations. Contrary to As4O6 arsenolite, a material of similar cage-like molecular structure, no pressure-induced helium penetration into the crystal structure was observed. Instead, two pressure-induced structural changes are observed. The first one is suggested by the following occurrences: (i) gradual quenching of the magnitudes of atomic displacement parameters, (ii) diminishing libration contribution to the experimental C−N bond length, (iii) discontinuity in calculated IR-active vibrational modes and (iv) asymptotically vanishing discrepancy between the experimental and DFT‑calculated unit cell volume. All these features reach a plateau at ~4 GPa and can be attributed to a damping of molecular librations and atomic thermal motion, pointing to the existence of a second-order isostructural phase transition. The second transformation, with an onset at ~12.5 GPa is a first-order phase transition to a tetragonal structure, characterized by sluggish kinetics and considerable hysteresis upon decompression. However, it occurs only in non-hydrostatic conditions, induced by a deviatoric stress in the sample. This behavior finds analogies in similar cubic crystals built of highly symmetric cage-like molecules and <a>may be considered a common feature</a> of such systems. Last but not least, it is worth noting successful Hirshfeld atom refinements, carried out for the incomplete high-pressure diffraction data up to 14 GPa, yielded more realistic C−H bond lengths than the independent atom model.

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A Practical Elastic Plastic Damage Model for Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.313 ◽

2011 ◽

Vol 243-249 ◽

pp. 313-318 ◽

Cited By ~ 3

Author(s):

Hu Qi ◽

Yun Gui Li ◽

Xi Lin Lu

Keyword(s):

Stress State ◽

Damage Mechanics ◽

Hydrostatic Stress ◽

Axial Stress ◽

Stress Component ◽

Damage Model ◽

Continuum Damage Mechanics ◽

Deviatoric Stress ◽

Elastic Plastic ◽

Plastic Damage

In this paper, an elastic plastic damage model is presented based on the combined use of elastic plastic constitutive equations along with continuum damage mechanics. A tensile and a compressive damage variable are adopted to describe the different responses of concrete under tension and compression, respectively. The Helmholtz Free Energy is decomposed into hydrostatic stress component and deviatoric stress components. The hydrostatic stress component is neglected and the deviatoric stress component is amended according to stress state, resulting in a more accurate description of the concrete’s response under multi-axial stress state. Finally, through several numerical simulations it is proved that the proposed model has the capability of simulating typical nonlinear performances of concrete material.

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Crystal Structure of Urotropine Under High Pressure and Non-Hydrostatic Stress-Induced Phase Transitions in Cage Compounds

10.26434/chemrxiv.12103233.v2 ◽

2020 ◽

Author(s):

Piotr A. Guńka ◽

Anna Olejniczak ◽

Samuele Fanetti ◽

Roberto Bini ◽

Ines E. Collings ◽

...

Keyword(s):

Crystal Structure ◽

Phase Transition ◽

High Pressure ◽

Structural Changes ◽

Hydrostatic Stress ◽

Atomic Displacement ◽

Deviatoric Stress ◽

Cage Compounds ◽

First Order Phase Transition ◽

Atomic Displacement Parameters

High-pressure behavior of hexamthyleneteramine (urotropine) was studied in situ using angle-dispersive single-crystal synchrotron X-ray diffraction (XRD) and Fourier transform infrared absorption (FTIR) spectroscopy. Experiments were conducted in various pressure transmitting media (helium and neon for XRD, nitrogen and KBr for FTIR experiments) to study the effect of deviatoric stress on phase transformations. Contrary to As4O6 arsenolite, a material of similar cage-like molecular structure, no pressure-induced helium penetration into the crystal structure was observed. Instead, two pressure-induced structural changes are observed. The first one is suggested by the following occurrences: (i) gradual quenching of the magnitudes of atomic displacement parameters, (ii) diminishing libration contribution to the experimental C−N bond length, (iii) discontinuity in calculated IR-active vibrational modes and (iv) asymptotically vanishing discrepancy between the experimental and DFT‑calculated unit cell volume. All these features reach a plateau at ~4 GPa and can be attributed to a damping of molecular librations and atomic thermal motion, pointing to the existence of a second-order isostructural phase transition. The second transformation, with an onset at ~12.5 GPa is a first-order phase transition to a tetragonal structure, characterized by sluggish kinetics and considerable hysteresis upon decompression. However, it occurs only in non-hydrostatic conditions, induced by a deviatoric stress in the sample. This behavior finds analogies in similar cubic crystals built of highly symmetric cage-like molecules and <a>may be considered a common feature</a> of such systems. Last but not least, it is worth noting successful Hirshfeld atom refinements, carried out for the incomplete high-pressure diffraction data up to 14 GPa, yielded more realistic C−H bond lengths than the independent atom model.

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Crystal structure and non-hydrostatic stress-induced phase transition of urotropine under high pressure

10.26434/chemrxiv.12103233.v3 ◽

2020 ◽

Author(s):

Piotr A. Guńka ◽

Anna Olejniczak ◽

Samuele Fanetti ◽

Roberto Bini ◽

Ines E. Collings ◽

...

Keyword(s):

Crystal Structure ◽

Phase Transition ◽

High Pressure ◽

Structural Changes ◽

Hydrostatic Stress ◽

Atomic Displacement ◽

Deviatoric Stress ◽

First Order Phase Transition ◽

Atomic Displacement Parameters ◽

First Order Phase

High-pressure behavior of hexamthyleneteramine (urotropine) was studied in situ using angle-dispersive single-crystal synchrotron X-ray diffraction (XRD) and Fourier transform infrared absorption (FTIR) spectroscopy. Experiments were conducted in various pressure transmitting media (helium and neon for XRD, nitrogen and KBr for FTIR experiments) to study the effect of deviatoric stress on phase transformations. Contrary to As4O6 arsenolite, a material of similar cage-like molecular structure, no pressure-induced helium penetration into the crystal structure was observed. Instead, two pressure-induced structural changes are observed. The first one is suggested by the following occurrences: (i) gradual quenching of the magnitudes of atomic displacement parameters, (ii) diminishing libration contribution to the experimental C−N bond length, (iii) discontinuity in calculated IR-active vibrational modes and (iv) asymptotically vanishing discrepancy between the experimental and DFT‑calculated unit cell volume. All these features reach a plateau at ~4 GPa and can be attributed to a damping of molecular librations and atomic thermal motion, pointing to the existence of a second-order isostructural phase transition. The second transformation, with an onset at ~12.5 GPa is a first-order phase transition to a tetragonal structure, characterized by sluggish kinetics and considerable hysteresis upon decompression. However, it occurs only in non-hydrostatic conditions, induced by a deviatoric stress in the sample. This behavior finds analogies in similar cubic crystals built of highly symmetric cage-like molecules and <a>may be considered a common feature</a> of such systems. Last but not least, it is worth noting successful Hirshfeld atom refinements, carried out for the incomplete high-pressure diffraction data up to 14 GPa, yielded more realistic C−H bond lengths than the independent atom model.

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Continuous out-of-sequence ductile thrusting in the Norwegian Caledonides

Geological Magazine ◽

10.1017/s0016756800016277 ◽

1987 ◽

Vol 124 (3) ◽

pp. 249-260 ◽

Cited By ~ 13

Author(s):

A. H. N. Rice

Keyword(s):

Hydrostatic Stress ◽

Deviatoric Stress ◽

Prograde Metamorphism ◽

Stress Regime ◽

Cooling Rates ◽

Thrust Plane ◽

Nappe Complex ◽

Nappe Emplacement ◽

Norwegian Caledonides

AbstractPeak metamorphic conditions (up to sillimanite grade) in a unit of rocks beneath the evolving Kalak Nappe Complex (Finnmarkian Caledonides) developed prior to its incorporation as a nappe within the complex. The presence of displacement textures in peak metamorphic por-phyroblasts indicates that they grew in a hydrostatic stress regime and thus that the emplacement of tectonically higher units caused little or no deviatoric stress in the footwall rocks except close to the thrust plane.The developing geotherm in the incipient nappe was disrupted by the onset of thrusting (D2 deformation), which placed hot rocks on colder rocks. This led to the cessation of prograde metamorphism and accounts for the ubiquitous association of nappe emplacement and the meta morphic peak. Later deformation (D3/D4) occurred at lower grades (biotite/chlorite). Consideration of nappe translation rates and the likely erosion/cooling rates indicates that nappe movements must have occurred ‘continuously out-of-sequence’ within the Kalak Nappe Complex.

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Crystal structure and non-hydrostatic stress-induced phase transition of urotropine under high pressure

10.26434/chemrxiv.12103233 ◽

2020 ◽

Author(s):

Piotr A. Guńka ◽

Anna Olejniczak ◽

Samuele Fanetti ◽

Roberto Bini ◽

Ines E. Collings ◽

...

Keyword(s):

Crystal Structure ◽

Phase Transition ◽

High Pressure ◽

Structural Changes ◽

Hydrostatic Stress ◽

Atomic Displacement ◽

Deviatoric Stress ◽

First Order Phase Transition ◽

Atomic Displacement Parameters ◽

First Order Phase

High-pressure behavior of hexamthyleneteramine (urotropine) was studied in situ using angle-dispersive single-crystal synchrotron X-ray diffraction (XRD) and Fourier transform infrared absorption (FTIR) spectroscopy. Experiments were conducted in various pressure transmitting media (helium and neon for XRD, nitrogen and KBr for FTIR experiments) to study the effect of deviatoric stress on phase transformations. Contrary to As4O6 arsenolite, a material of similar cage-like molecular structure, no pressure-induced helium penetration into the crystal structure was observed. Instead, two pressure-induced structural changes are observed. The first one is suggested by the following occurrences: (i) gradual quenching of the magnitudes of atomic displacement parameters, (ii) diminishing libration contribution to the experimental C−N bond length, (iii) discontinuity in calculated IR-active vibrational modes and (iv) asymptotically vanishing discrepancy between the experimental and DFT‑calculated unit cell volume. All these features reach a plateau at ~4 GPa and can be attributed to a damping of molecular librations and atomic thermal motion, pointing to the existence of a second-order isostructural phase transition. The second transformation, with an onset at ~12.5 GPa is a first-order phase transition to a tetragonal structure, characterized by sluggish kinetics and considerable hysteresis upon decompression. However, it occurs only in non-hydrostatic conditions, induced by a deviatoric stress in the sample. This behavior finds analogies in similar cubic crystals built of highly symmetric cage-like molecules and <a>may be considered a common feature</a> of such systems. Last but not least, it is worth noting successful Hirshfeld atom refinements, carried out for the incomplete high-pressure diffraction data up to 14 GPa, yielded more realistic C−H bond lengths than the independent atom model.

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