B.B. Karki¹, D. Bhattarai¹, L. Stixrude²

CMC-Computers, Materials & Continua, Vol.3, No.3, pp. 107-118, 2006, DOI:10.3970/cmc.2006.003.107

Abstract Computer modeling of liquid phase poses tremendous challenge: It requires a relatively large simulation size, long simulation time and accurate interatomic interaction and as such, it produces massive amounts of data. Recent advances in hardware and software have made it possible to accurately simulate the liquid phase. This paper reports the details of methodology used in the context of liquid simulations and subsequent analysis of the output data. For illustration purpose, we consider the results for the liquid phases of two geophysically relevant materials, namely MgO and MgSiO₃. The simulations are performed using the parallel first-principles molecular dynamics (FPMD) technique… More >

Lingfei Gao¹, Xiaoping Zheng^1,2, Zhenhan Yao¹

CMC-Computers, Materials & Continua, Vol.3, No.1, pp. 25-36, 2006, DOI:10.3970/cmc.2007.003.025

Abstract A general numerical approach is developed to model the elastic behaviours and failure processes of heterogeneous materials. The heterogeneous material body is assumed composed of a large number of convex polygon lattices with different phases. These phases are locally isotropic and elastic-brittle with the different lattices displaying variable material parameters and a Weibull-type statistical distribution. When the effective strain exceeds a local fracture criterion, the full lattice exhibits failure uniformly, and this is modelled by assuming a very small Young modulus value. An auto-select loading method is employed to model the failure process. The proposed hybrid approach is applied to… More >

Carlos J. S. Alves, Pedro R. S. Antunes¹

CMC-Computers, Materials & Continua, Vol.2, No.4, pp. 251-266, 2005, DOI:10.3970/cmc.2005.002.251

Abstract In this work we show the application of the Method of Fundamental Solutions(MFS) in the determination of eigenfrequencies and eigenmodes associated to wave scattering problems. This meshless method was already applied to simple geometry domains with Dirichlet boundary conditions (cf. Karageorghis (2001)) and to multiply connected domains (cf. Chen, Chang, Chen, and Chen (2005)). Here we show that a particular choice of point-sourcescan lead to very good results for a fairly general type of domains. Simulations with Neumann boundary conditionare also considered. More >

Ramana M. Pidaparti¹, Anuj Puri², Mathew J. Palakal², Ajay Kashyap³

CMC-Computers, Materials & Continua, Vol.2, No.1, pp. 65-76, 2005, DOI:10.3970/cmc.2005.002.065

Abstract A two-dimensional corrosion initiation and growth model for aircraft aluminum materials is developed. The model takes into account the electro-chemical parameters as well as specific rules governing corrosion mechanisms. The simulation program is implemented in a cellular automata framework. The corrosion initiation and growth patterns obtained from simulations are compared qualitatively and quantitatively to the experimental data obtained from the Center for Materials Diagnostics at the University of Dayton Research Institute, Dayton. The results indicate that the present model effectively captures the corrosion damage process including initiation and growth. The effects of various electro-chemical parameters on the damage growth obtained… More >

K.Udaya Bhaskar^1,2, Sumit Tiwari², N. Ramakrishnan²

CMC-Computers, Materials & Continua, Vol.2, No.1, pp. 13-22, 2005, DOI:10.3970/cmc.2005.002.013

Abstract The investigation pertains to establishing a simulation methodology for understanding the separation characteristics of a typical hydrocyclone where the work was carried out using a commercially available CFD software. The studies included water flow profiles, water throughput {\&} product split, particle distribution etc. and the simulated results are further validated with suitably performed experiments. The work essentially highlights the performance of the hydrocyclone using numerical studies where water is used as a primary phase and solid particles as secondary ones. This methodology is expected to be useful in the design of hydrocyclones and optimizing the processes. More >

B. Wang¹, H.Q. Zhang¹, C.K. Chan², X.L. Wang¹

CMC-Computers, Materials & Continua, Vol.1, No.3, pp. 275-288, 2004, DOI:10.3970/cmc.2004.001.275

Abstract Dilute gas-particle turbulent flow over a backward-facing step is numerically simulated. Large Eddy Simulation (LES) is used for the continuous phase and a Lagrangian trajectory method is adopted for the particle phase. Four typical locations in the flow field are chosen to investigate the two-phase velocity fluctuations. Time-series velocities of the gas phase with particles of different sizes are obtained. Velocity of the small particles is found to be similar to that of the gas phase, while high frequency noise exists in the velocity of the large particles. While the mean and rms velocities of the gas phase and small… More >

L. Chernin¹, K.Y. Volokh^1,2

CMC-Computers, Materials & Continua, Vol.1, No.3, pp. 259-274, 2004, DOI:10.3970/cmc.2004.001.259

Abstract The conventional approach to analysis of thin film delamination is based on the consideration of the film, which is subjected to residual stresses arising from the thermal mismatch between the film and the substrate, within the framework of the classical fracture mechanics and the structural buckling theories. Such concepts as the energy release rate and the stress intensity factors are crucial in this case.

A different approach to analysis of thin film delamination considers the effect of the compliant interface between the film and the substrate. This compliant interface is described by the traction-separation constitutive law.

… More >

C. H. Cheng¹, S. C. Chen²

CMC-Computers, Materials & Continua, Vol.1, No.3, pp. 205-212, 2004, DOI:10.3970/cmc.2004.001.205

Abstract A shear mode piezoelectric actuator is applied to deflect the diaphragm of pressure chamber in the droplet ejector or inkjet printhead. The deflection of the bulge-diaphragm and resulting swept volume is analyzed by analytical and numerical method. With free-body treatment of the model, the analytical exact solutions for the two free bodies of bulge-diaphragm and piezoelectric beam were obtained. Also, the numerical solution by ANSYS is obtained to verify the analytical result. Besides, the whole-model solution coupling the bulge-diaphragm and piezoelectric beam together was obtained by ANSYS to compare with the result of free-body analysis. In order to estimate the… More >