Stress Field Numerical Calculation for T10 Steel Quenched by Atmosphere-Pressure High-Velocity Nitrogen-Water Spray Based on DEFORM

2013 ◽  
Vol 444-445 ◽  
pp. 1118-1121
Author(s):  
Liu Chuang Wei ◽  
He Ming Cheng ◽  
Jian Yun Li ◽  
Xue Zhang ◽  
Si Qing Zhou ◽  
...  
Keyword(s):  
Stress Field ◽  
Accurate Result ◽  
Estimation Method ◽  
Steel Specimen ◽  
Calculation Model ◽  
Fortran Program ◽  
Water Spray ◽  
Accurate Calculation ◽  
Atmosphere Pressure ◽  
Quenching Process

In this paper, by using the result calculated with FORTRAN program based on nonlinear estimation method, the stress field of T10 steel specimen quenching process is solved and analyzed. In order to get an in-depth understanding of the stress field in the specimen, the accurate calculation model and appropriate simplification must be considered. Because T10 steels phase is non-uniform when quenching, in order to get the accurate result, the heat release of phase changing must be considerate.

Simulation on Torpedo Unsteady Hydrodynamic with the Movement in the Longitudinal Plane

2013 ◽  
Vol 791-793 ◽  
pp. 1073-1076
Author(s):  
Ming Yang ◽  
Shi Ping Zhao ◽  
Han Ping Wang ◽  
Lin Peng Wang ◽  
Shao Zhu Wang
Keyword(s):  
Three Dimensional ◽  
Engineering Application ◽  
Calculation Model ◽  
Trajectory Design ◽  
Design Calculation ◽  
Variable Speed ◽  
Accurate Calculation ◽  
Longitudinal Plane ◽  
Submerged Body ◽  
Mesh Method

The unsteady hydrodynamic accurate calculation is the premise of submerged body trajectory design and maneuverability design. Calculation model of submerged body unsteady hydrodynamic with the movement in the longitudinal plane was established, which based on unsteady three-dimensional incompressible fluid dynamics theory. Variable speed translational and variable angular velocity of the pitching motion in the longitudinal plane of submerged body was achieved by dynamic mesh method. The unsteady hydrodynamic could be obtained by model under the premise of good quality grid by the results. Modeling methods can learn from other similar problems, which has engineering application value.

scholarly journals Local stress fields in solids estimated by acoustical emission method

2021 ◽  
Vol 2103 (1) ◽  
pp. 012064
Author(s):  
V L Hilarov ◽  
E E Damaskinskaya
Keyword(s):  
Time Series ◽  
Acoustic Emission ◽  
Stress Field ◽  
Estimation Method ◽  
Local Stress ◽  
Stress Fields ◽  
Emission Method ◽  
Macroscopic Fracture ◽  
Stress Estimation ◽  
Kinetic Concept

Abstract Based on the Zhurkov’s kinetic concept of solids’ fracture a local internal stress estimation method is introduced. Stress field is computed from the time series of acoustic emission intervals between successive signals. For the case of two structurally different materials the time evolution of these stresses is examined. It is shown that temporal changes of these stresses’ accumulation law may serve as a precursor of incoming macroscopic fracture.

Transient Response of an Interface-Crack in a Layered Plate

1986 ◽  
Vol 53 (3) ◽  
pp. 579-586 ◽  
Author(s):  
T. Kundu
Keyword(s):  
Stress Field ◽  
Interface Crack ◽  
Transient Response ◽  
Singular Integrals ◽  
Fortran Program ◽  
Numerical Results ◽  
New Method ◽  
Layered Plate ◽  
Improved Method ◽  
Sample Problem

In this paper, the transient response of an interface crack, in a two layered plate subjected to an antiplane stress field, is analytically computed. The problem is formulated in terms of semi-infinite integrals following the technique developed by Neerhoff (1979). It has been shown that the major steps of Neerhoff’s technique, which was originally developed for layered half-spaces, can also be applied to layered plate problems. An improved method for manipulation of semi-infinite singular integrals is also presented here. Finally, the new method is coded in FORTRAN program and numerical results for a sample problem are presented.

Investigations on Residual Stress Distribution for 2A02 Aluminum Forgings

2013 ◽  
Vol 853 ◽  
pp. 135-142
Author(s):  
Jiang Cao ◽  
Chun Fu Li ◽  
Yan Wang ◽  
Xing Sun ◽  
Shu Yun Wang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Stress Field ◽  
Residual Stress Distribution ◽  
Indentation Method ◽  
Absolute Value ◽  
Element Simulation ◽  
Quenching Process ◽  
Micro Indentation

High strength aluminum alloys have been widely used in aviation manufacturing due to their favorable combination of intensity, stress corrosion resistance and toughness. However, the research and control of residual stress distribution in aluminum components have become a key issue to be solved during the heat treatment and subsequent processes. By means of the analysis of micro-indentation method and ANSYS finite element method, the residual stress distribution in 2A02 aluminum components after water quenching were systematically investigated, mainly considering two factors of the symmetry of structure and the variation of surface constraint. This study may give great help to the technology of relieving forgings residual stress of two alloys.The results of micro-indentation method show that the absolute value of the residual stress within the sample tends to decrease as the condition of constraint increase at the location of the same thickness; the absolute value of the surface residual stress also tends to decrease as the thickness of the sample increase with the same constraint conditions. The tested results by micro-indentation method are in consistent with the results of finite element simulation to a great extent.The results of finite element simulation are as follows: for these two aluminum alloy, the stress field distribution during the process of quenching is mainly influenced by the thickness of the samples. In general, at the initial stage of the quenching process, the stress state at the components surface are controlled by tensile stress in the direction of both thickness and width, while the residual stress within the samples is dominated by compressive stress; at the end of the quenching process, the stress field distribution just turn to the opposite. These results are in great agreement with the corresponding results of the indentation method.

An accurate calculation model of solar heat gain through glazed surfaces

2011 ◽  
Vol 43 (2-3) ◽  
pp. 269-274 ◽  
Author(s):  
Giuseppe Oliveti ◽  
Natale Arcuri ◽  
Roberto Bruno ◽  
Marilena De Simone
Keyword(s):  
Calculation Model ◽  
Accurate Calculation ◽  
Heat Gain ◽  
Solar Heat ◽  
Solar Heat Gain

Ultralow Permeability Reservoir Stress Field Simulation

2013 ◽  
Vol 816-817 ◽  
pp. 728-733
Author(s):  
Guang Feng Liu ◽  
Yang Lu ◽  
Ling Lu ◽  
Jun Tao Wang
Keyword(s):  
Stress Field ◽  
Simulation Method ◽  
In Situ Stress ◽  
Calculation Model ◽  
Element Analysis ◽  
Pattern Design ◽  
The Maximum Principle ◽  
Inversion Principle ◽  
Well Pattern ◽  
Ultralow Permeability

The simulation method of reservoir tectonic and present stress field was recommended, and in-situ stress distribution of C82 ultralow permeability reservoir formation in Changqing oilfied Z19 well block was computed. The method is based on finite element analysis, of which the contents and procedures include geological model establishment, calculation model establishment and results analysis. The simulation precision depends on the reliability of models. Inversion criteria need to be set to determine whether the ultimate simulating result is reasonable. Main inversion criteria include absolute inversion, principle stress criteria, deformation criteria, etc. The maximum principle stress value of C82 formation in Z19 well block is between 35.7 and 45.2MPa, whose direction is NE 72o-80o, and the dominant direction is NE 75o. The differential stress value is between 0.4 and 9.8MPa. The relationship between stress, reservoir parameters and production data was discussed. The simulation results can be taken as reference for well pattern design, optimization and overall fracturing design.

Kinematical measurement of hydraulic tortuosity of fluid flow in porous media

2015 ◽  
Vol 26 (02) ◽  
pp. 1550017 ◽  
Author(s):  
Y. Jin ◽  
J. B. Dong ◽  
X. Li ◽  
Y. Wu
Keyword(s):  
Porous Media ◽  
Flow Direction ◽  
Estimation Method ◽  
Mean Value ◽  
Calculation Model ◽  
Flow In Porous Media ◽  
Porous Media Flow ◽  
Average Value ◽  
The Mean ◽  
The Impact

It is hard to experimentally or analytically derive the hydraulic tortuosity (τ) of porous media flow because of their complex microstructures. In this work, we propose a kinematical measurement method for τ by introducing the concept of local tortuosity, which is defined as the ratio of fluid particle velocity to its component along the macro flow. And then, the calculation model of τ is analytically deduced in terms of that τ is the mean value of the local tortuosity. To avoid the impact from the singularity of local tortuosity, the velocity is normalized, and τ is then approximated by the ratio of the mean normalized velocity to the average value of its component along the macro-flow direction. The new estimation method is verified by flow through different types of porous media via the lattice Boltzmann method, and the relationships between permeabilities and tortuosities obtained by different methods are examined. The numerical results show that tortuosity by the novel approach is in good agreement with the existing theory, and the kinematic definition of hydraulic tortuosity is also proven.

Study on Coupling Effect of Hydrogen Pressure Stress Field of Micropores in the Heavy Forgings

2014 ◽  
Vol 884-885 ◽  
pp. 324-328
Author(s):  
Feng Shan Du ◽  
Jie Li ◽  
Jun Kai Fan ◽  
Yuan Li ◽  
Tian Yu Tan
Keyword(s):  
Stress Field ◽  
Relative Position ◽  
Hydrogen Pressure ◽  
Coupling Effect ◽  
Calculation Model ◽  
Field Analysis ◽  
Finite Element Software ◽  
Micro Cracks ◽  
Stress Field Analysis ◽  
Pressure Stress

On the basis of the principle of hydrogen pressure, this paper makes a comprehensive research about coupling effect of the stress field in the micropores in the condition of hydrogen pressure. According to the equation of Kazinczy Pokinger, calculation model of hydrogen pressure strength of the micropores in the heavy forgings is established with the temperature and hydrogen content. Summarize the relative position of crack in the forgings into four combinations, and use the finite element software to analyze the coupling strength of four different combinations of cracks under hydrogen pressure stress field. Analysis results show that, different relative position relationship between cracks and the size of the micro cracks have different effect on coupling effect of hydrogen pressure stress field in micro cracks.

scholarly journals Numerical investigation of the transient spray cooling process for quenching applications

2018 ◽  
Vol 22 (5) ◽  
pp. 1943-1953 ◽  
Author(s):  
Jakov Baleta ◽  
Fengsheng Qi ◽  
Marija Zivic ◽  
Martina Lovrenic-Jugovic
Keyword(s):  
Heat Transfer ◽  
Relevant Literature ◽  
Spray Cooling ◽  
Heat Transfer Process ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Wall Heat Transfer ◽  
Water Spray ◽  
Quenching Process ◽  
Particle Velocities

Water spray quenching distinguished itself as a promising method for industry production, especially for the parts which require good mechanical strength while simultaneously retaining the initial toughness. Studies have shown that the heat transfer process during the spray quenching is mostly influenced by the spray impingement density, particle velocities and sizes. The application of advanced numerical methods still plays insufficient role in the development of the production process, in spite of the fact that industry today is facing major challenges that can be met only by development of new and more efficient systems using advanced tools for product development, one of which is CFD. Taking the above stated, the object of this research is numerical simulation of spray quenching process in order to determine validity of mathematical models implemented within the commercial CFD code Fire, especially droplet evaporation/condensation and droplet-wall heat transfer model. After review of the relevant literature suitable benchmark case was selected and simulated by employing discrete droplet method for the spray treatment and Eulerian approach for the gas phase description. Simulation results indicated that existing droplet/wall heat transfer model is not able to reproduce heat transfer of dense water spray. Thus, Lagrangian spray model was improved by implementing experimental correlation for heat transfer coefficient during spray quenching. Finally, verification of the implemented model was assessed based on the conducted simulations and recommendations for further improvements were given.

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