The Experts below are selected from a list of 91134 Experts worldwide ranked by ideXlab platform
Marc C. Fivel - One of the best experts on this subject based on the ideXlab platform.
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Bubble collapse induced cavitation erosion: Plastic Strain and energy dissipation investigations
Journal of the Mechanics and Physics of Solids, 2020Co-Authors: Shrey Joshi, Jean-pierre Franc, Giovanni Ghigliotti, Marc C. FivelAbstract:A meshless Smoothed Particle Hydrodynamics solver is used to simulate the collapse of a cavitation bubble near a solid material taking into account the complex fluid-structure interaction. A parametric study has been performed to study the effect of stand-off ratio, bubble size, driving pressure and Strain rate on the material response. We focus on Plastic Strain magnitudes and Plastic Strain energy dissipation to compare different cases and their ability to cause material erosion. Findings indicate that, in the case of repeated collapses, cavities attached to the solid have an ability to initiate damage quicker but exhibit lower erosion rate compared to the cavities detached from the solid. The incubation time does not depend on the size of the bubbles, unlike the erosion rate which is strongly affected by the bubble size. It is also found that the amount of cumulated Plasticity is overestimated by more than 150% when the Strain-rate sensitivity is not taken into account in the material modelling which suggests that using an appropriate Plasticity model that includes Strain-rate sensitivity is mandatory while studying the phenomenon of cavitation erosion.
E A Patterson - One of the best experts on this subject based on the ideXlab platform.
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quantitative measurement of Plastic Strain field at a fatigue crack tip
Proceedings of The Royal Society A: Mathematical Physical and Engineering Sciences, 2012Co-Authors: Y Yang, M A Crimp, R A Tomlinson, E A PattersonAbstract:A novel approach is introduced to map the mesoscale Plastic Strain distribution resulting from heterogeneous Plastic deformation in complex loading and component geometries, by applying the discret...
Valery I Levitas - One of the best experts on this subject based on the ideXlab platform.
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coupled elastoPlasticity and Plastic Strain induced phase transformation under high pressure and large Strains formulation and application to bn sample compressed in a diamond anvil cell
International Journal of Plasticity, 2017Co-Authors: Biao Feng, Valery I LevitasAbstract:Abstract In order to study high-pressure phase transformations (PTs), high static pressure is produced by compressing a thin sample within a high strength gasket in a diamond anvil cell (DAC). However, since a PT occurs during Plastic flow, it is classified and treated here as a Plastic Strain-induced PT. A thermodynamically consistent system of equations for combined Plastic flow and Plastic Strain-induced PTs is formulated for large elastic, Plastic, and transformation Strains. The Murnaghan elasticity law, pressure-dependent J2 Plasticity (both dependent of the concentration of a high-pressure phase), and Plastic Strain-induced and pressure-dependent PT kinetics are utilized. A computational algorithm within finite element method (FEM) is presented and implemented in a user material subroutine (UMAT) in the FEM code ABAQUS. Combined Plastic flow and Strain-induced PT from the highly-disordered hexagonal boron nitride (hBN) sample to a superhard wurtzitic wBN is simulated within the rhenium gasket for pressures up to 50 GPa. The evolution of the fields of stresses and Plastic Strains, as well as the concentration of phases in a sample is obtained and discussed in detail. Stress-Strain fields in a gasket and diamond are presented as well. An unexpected shape of the deformed sample with almost complete PT in the external part of the sample that penetrated the gasket was found. Obtained results demonstrated the difference between material and system behavior which are often confused by experimentalists. Thus, while Plastic Strain-induced PT may start (and end) at Plastic Straining slightly above 6.7 GPa, it is not visible below 12 GPa. It becomes detectable at 21 GPa and is not completed everywhere in a sample even at a maximum pressure of 50 GPa. Due to a strong gasket the gradient of pressure is much smaller than the gradient of Plastic Strain, and therefore the distribution of the high pressure phase is mostly determined by the Plastic Strain field instead of the pressure field. Possible misinterpretation of the experimental data and characterization of the PT is discussed. The developed model will allow computational design of experiments for synthesis of high-pressure phases.
Shrey Joshi - One of the best experts on this subject based on the ideXlab platform.
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Bubble collapse induced cavitation erosion: Plastic Strain and energy dissipation investigations
Journal of the Mechanics and Physics of Solids, 2020Co-Authors: Shrey Joshi, Jean-pierre Franc, Giovanni Ghigliotti, Marc C. FivelAbstract:A meshless Smoothed Particle Hydrodynamics solver is used to simulate the collapse of a cavitation bubble near a solid material taking into account the complex fluid-structure interaction. A parametric study has been performed to study the effect of stand-off ratio, bubble size, driving pressure and Strain rate on the material response. We focus on Plastic Strain magnitudes and Plastic Strain energy dissipation to compare different cases and their ability to cause material erosion. Findings indicate that, in the case of repeated collapses, cavities attached to the solid have an ability to initiate damage quicker but exhibit lower erosion rate compared to the cavities detached from the solid. The incubation time does not depend on the size of the bubbles, unlike the erosion rate which is strongly affected by the bubble size. It is also found that the amount of cumulated Plasticity is overestimated by more than 150% when the Strain-rate sensitivity is not taken into account in the material modelling which suggests that using an appropriate Plasticity model that includes Strain-rate sensitivity is mandatory while studying the phenomenon of cavitation erosion.
Kaneaki Tsuzaki - One of the best experts on this subject based on the ideXlab platform.
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roles of hydrogen and Plastic Strain distribution on delayed crack growth in single crystalline fe si alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2021Co-Authors: Kaneaki Tsuzaki, Thanh Thuong Huynh, Shigeru Hamada, Hiroshi NoguchiAbstract:Abstract Effects of hydrogen on macroscopic and microscopic features of crack growth in thin specimens were investigated using a thin sheet of single-crystal Fe-3wt%Si alloy. Center-cracked specimens were tested under a sustained load in a hydrogen environment, and under continuous stretching in an air environment. The fracture features were compared to elucidate the role of hydrogen in hydrogen-induced delayed crack growth. In both air and hydrogen environments, the crack growth mode of the thin specimens was the same as that of the thick specimens, despite the significantly reduced thickness. Surprisingly, the crack grew discontinuously, and left striations on the fracture surface, in which shorter striation spacing was observed in hydrogen. In addition, there was a similarity in the deformation microstructures beneath the fracture surface, that is, both microstructures were composed of three distinct layers characterized by different Plastic Strain gradients and dislocation densities. In the hydrogen environment, the hydrogen-enhanced localized Plasticity (HELP) mechanism is believed to be relevant to the crack growth process. Also, HELP was supposed to cause different characteristics (the magnitude of Plastic Strain, the Plastic Strain gradient, and dislocation structure) of the three layers in the hydrogen compared to those in the air. Reverse Plastic deformation occurred in the regions behind the crack front during crack growth, which is speculated to contribute not only to enlarge the crack tip opening angle (CTOA) but also to blunt the crack tip.
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effect of Plastic Strain on grain size of ferrite transformed from deformed austenite in si mn steel
Materials Science and Technology, 2001Co-Authors: Tadanobu Inoue, Shiro Torizuka, Kotobu Nagai, Kaneaki Tsuzaki, T OhashiAbstract:AbstractThe effect of Plastic Strain on the grain size of ferrite transformed from deformed and unrecrystallised austenite has been investigated for a low carbon Si-Mn steel. An explicit finite element technique was used to evaluate the Plastic Strain distribution introduced by deformation in a specimen. The specimen was compressed by a pair of anvils controlled to keep the Strain rate constant. The contact condition between the anvil and the specimen was determined by the experimental result from an identically deformed screw set in the specimen. The interrelation between the equivalent Plastic Strain epsiloneq, numerically obtained in the range 0.1
