Phase Field Simulation of Coarsening Kinetics in Al-Sc and Al-Sc-Zr Alloys

2008 ◽  
Vol 1128 ◽  
Author(s):  
H. Zapolsky ◽  
J. Boisse ◽  
R. Patte ◽  
N. Lecoq

AbstractThe coarsening kinetics of γ’ precipitates in binary and ternary Al3Sc1-xZrx alloys is studied by using the two- and three-dimensional phase-field simulations. Our focus is on the influence of diffusion coefficients of Sc and Zr atoms on the transformation path kinetics from disordered f.c.c. matrix to two phases equilibrium state with γ’ precipitates and f.c.c. disordered matrix. Our simulation results demonstrate that in the case of binary alloys taking into account the concentration dependence of the mobility of atoms decreases the coarsening rate. In the case of ternary alloys we show that the Al3Sc particles precipitate first following by appearance of a Zr-rich shell. Our simulations results are in good agreement with experimental observations.

2004 ◽  
Vol 52 (9) ◽  
pp. 2837-2845 ◽  
Author(s):  
J.Z. Zhu ◽  
T. Wang ◽  
A.J. Ardell ◽  
S.H. Zhou ◽  
Z.K. Liu ◽  
...  

2007 ◽  
Vol 353-358 ◽  
pp. 1072-1077 ◽  
Author(s):  
Ren Ping Shao ◽  
Xin Na Huang ◽  
Pu Rong Jia ◽  
Wan Lin Guo ◽  
Kaoru Hirota

A method of damage detection and fault diagnosis for gears is presented based on the theory of elastomeric dynamics according to the theory of cracked beam. It takes an advantage of accurate fault diagnosis of gear body using the change of dynamic features and has some advantages for dynamic design of gear systems.The dynamics characteristics, i.e., natural frequency, vibration shape,dynamic response and so on, due to crack of gear tooth are studied, and the gear dynamics characteristics caused by the position and size of crack are deeply investigated by comparison with FEM. The theoretical analysis results are contrasted with numerical simulation results and shows good agreement with the result by FEM. The proposed method can be used to detect damage and diagnose fault for gear structures and also can be applied to designing dynamic characteristics for gear systems.


2011 ◽  
Vol 399-401 ◽  
pp. 1768-1772 ◽  
Author(s):  
Chang Bo Ke ◽  
Shan Shan Cao ◽  
Xiao Ma ◽  
Xin Ping Zhang

A three-dimensional phase field model applicable for the B2-B19′ martensitic phase transformation of NiTi alloys was developed to predict the twinning modes in the B2-B19′ transition. The phase field simulation results showed that by taking into account the transformation induced elastic strain, the martensite variants were self-accommodated and sheared along the specific interface in the entire transition stage for reducing the elastic energy, whether the formed interface between the variants belongs to twinning plane could be determined by calculating the minimum value of long range elastic interaction energy, Bpq. Through comparison with the existing analytical solutions, it is demonstrated that the phase field model can be used to predict the type I twinning modes in the B2-B19′ phase transition with good precision.


2010 ◽  
Vol 638-642 ◽  
pp. 2724-2729
Author(s):  
Yoshiyuki Saito ◽  
Chitoshi Masuda

Thermodynamic stability of Grain boundary in materials under severe plastic deformation was simulated by the Monte Carlo and the phase field methods. Computer simulations were performed on 3-dimensional textured materials. The Monte Carlo simulation results were qualitatively in good agreement with those by the phase field model. The classification of the solution of differential equations based on the mean-field Hillert model describing temporal evolution of the scaled grain size distribution function was in good agreement with those given by the Computer simulations. The ARB experiments were performed for pure Al and Al alloys-sheets in order to validate the computer simulation results concerning the grain boundary stability of textured materials. With use of the Monte Carlo and the phase field methods. Effect of grain boundary mobilises and interface energy given by the computer simulations.


2009 ◽  
Vol 19 (02) ◽  
pp. 651-660 ◽  
Author(s):  
GUOSI HU

This letter presents a new hyperchaotic system, which was obtained by adding a nonlinear quadratic controller to the first equation and a linear controller to the second equation of the three-dimensional autonomous modified Lorenz chaotic system. This system uses only two multipliers but can generate very complex strange attractors with three positive Lyapunov exponents. The system is not only demonstrated by numerical simulations but also implemented via an electronic circuit, showing very good agreement with the simulation results.


2011 ◽  
Vol 62 (4) ◽  
pp. 220-226 ◽  
Author(s):  
Ali Mosallanejad ◽  
Abbas Shoulaie

Calculation and Measurement of Coil Inductance Profile in Tubular Linear Reluctance Motor and its Validation by Three Dimensional FEMThis paper reports a study of coil inductance profile in all positions of plunger in tubular linear reluctance motors (TLRMs) with open type magnetic circuits. In this paper, maximum inductance calculation methods in winding of tubular linear reluctance motors are described based on energy method. Furthermore, in order to calculate the maximum inductance, equivalent permeability is measured. Electromagnetic finite-element analysis for simulation and calculation of coil inductance in this motor is used. Simulation results of coil inductance calculation using 3-D FEM with coil current excitation is compared to theoretical and experimental results. The comparison yields a good agreement.


2020 ◽  
Vol 143 ◽  
pp. 103314 ◽  
Author(s):  
Douglas E. Spearot ◽  
Vincent Taupin ◽  
Khanh Dang ◽  
Laurent Capolungo

2021 ◽  
Author(s):  
Chao Hu ◽  
Xiao-liang Wang ◽  
Qing-quan Liu

<p>The calving of large-scale icebergs into the sea can generate a local tsunami that may threaten coastal communities or passing ships. A three-dimensional smoothed particle hydrodynamics model of rigid-body–fluid system is established to simulate the spatial wave generated by calving iceberg. The model is tested with simulated waves induced by a cube iceberg fall into the water body. Good agreement is obtained between simulation results and experimental data. The generation and evolution processes, and the near flow-field characteristics of the waves are analyzed. The simulation results show that waves generated in iceberg calving can generate not only a huge leading wave but also notable tailing waves. The initial propagation direction of the leading wave is determined by iceberg geometry, but as the leading wave propagates away, the water level displacement gradually develops into a semicircle wavefront which is irrelevant to iceberg geometry.</p>


1962 ◽  
Vol 84 (1) ◽  
pp. 29-38 ◽  
Author(s):  
R. Moissis ◽  
P. Griffith

This paper describes quantitatively one stage of the flow development process in equipment working with two-phase mixtures. The kinetics of a Taylor bubble, as it rises behind a series of other bubbles in a gas-liquid slug flow, have been determined. The rise velocity of a bubble is expressed as a function of separation distance from the bubble ahead of it. Using this information, the pattern of development of bubbles which initially enter a tube at regular intervals is determined by means of finite difference calculations. The density and, to a first approximation the pressure drop, of the developing flow are then calculated from continuity considerations. The density distribution in the entrance region is found to be a function of flow rates of the two phases, of distance from the inlet, and of initial bubble size. Density calculated by the present theory is compared with experimental measurements by the present and other investigators. Theory and experiments are in good agreement.


Sign in / Sign up

Export Citation Format

Share Document