Charles E. Anderson, Jr.¹, Matthew S. Burkins², James D. Walker¹, William A. Gooch²

CMES-Computer Modeling in Engineering & Sciences, Vol.8, No.2, pp. 91-104, 2005, DOI:10.3970/cmes.2005.008.091

Abstract A modification of Wilkins computational ceramics model is used to simulate experiments of the impact of the APM2 bullet against boron carbide/aluminum targets. Flash radiography provides time-resolved penetration histories. The simulation results are compared to the experimental data; generally, agreement is very good, including capturing dwell and then the onset of penetration. Crater width and debris diameter are also reproduced by the simulations reasonably well. A critical discussion of deficiencies of this computational engineering model is provided. More >

Toshihisa Nishioka ¹,

CMES-Computer Modeling in Engineering & Sciences, Vol.10, No.3, pp. 209-216, 2005, DOI:10.3970/cmes.2005.010.209

Abstract Recent Advances in Numerical Simulation Technologies for Various Dynamic Fracture Phenomena are summarized. First, the basic concepts of fracture simulations are explained together with pertinent simulation results. Next, Examples of dynamic fracture simulations are presented. More >

Y. Yan¹, V. Shevtsova², M. Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.4, pp. 315-328, 2005, DOI:10.3970/fdmp.2005.001.315

Abstract Convection has a major impact on diffusion in fluid mixtures either on the Earth or in the microgravity condition. G-jitters, as the primary source that induces the vibrational convection in space laboratories, should be studied thoroughly in order to improve the diffusion-dominated fluid science experiments. In this paper we consider the effect of g-jitters on thermal diffusion. The mixture water-isopropanol (90:10 wt%) bounded in a cubic cell is simulated with a lateral heating and various vibration conditions. The fluid flow, concentration and temperature distributions are thoroughly analyzed for different g-jitter scenarios. It is shown that… More >

T. Tsukada¹, M. Kobayashi², C. J. Jing³, N. Imaishi⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.1, pp. 45-62, 2005, DOI:10.3970/fdmp.2005.001.045

Abstract In this paper, our recent numerical studies on the Czochralski (CZ) crystal growth of oxide are surveyed. In the first part of the analysis, a "global" heat transfer model for an inductively heated CZ furnace is introduced and depicted in detail. It is emphasized that accounting for the internal radiation within the crystal and/or melt is of crucial importance since they are often semitransparent to infrared radiation. Results coming from such a "global" approach suggest that the melt/crystal interface shape is strongly affected by the optical properties of the crystal, of the melt and by More >

F. Auricchio¹, L. Petrini², R. Pietrabissa³, E. Sacco⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 365-380, 2003, DOI:10.3970/cmes.2003.004.365

Abstract Since 80’s many devices were developed to exploit the unique blend of mechanical and biocompatibility properties of shape memory alloys in orthodontic applications. It results in a high clinical effectiveness, but also in a spreading of technical knowledge on the properties of the single appliances. The goal of the present contribution is to contrast this sense of bewilderness and to prepare the basis for a simulationtool able to support the orthodontist choice. In particular a finite-element beam with a one-dimensional constitutive law, able to describe the SMA super elasticity and shape memory effect, is presented: More >

P. Zhang¹, P. Klein², Y. Huang^1,3, H. Gao⁴, P. D. Wu⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.2, pp. 263-278, 2002, DOI:10.3970/cmes.2002.003.263

Abstract The recently developed virtual-internal-bond (VIB) model has incorporated a cohesive-type law into the constitutive law of solids such that fracture and failure of solids become a coherent part of the constitutive law and no separate fracture or failure criteria are needed. A numerical algorithm is developed in this study for the VIB model under static loadings. The model is applied to study three examples, namely the crack nucleation and propagation from stress concentration, kinking and subsequent propagation of a mode II crack, and the buckling-driven delamination of a thin film from a substrate. The results More >

Haruhiko Kohno, Takahiko Tanahashi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.2, No.2, pp. 155-170, 2001, DOI:10.3970/cmes.2001.002.155

Abstract Three-dimensional (3D) unsteady numerical simulations are carried out by means of the finite element method (FEM) with the generalized simplified marker and cell (GSMAC) method in silicon melt with a non-deformable free surface with Prandtl number Pr = 1.8534 × 10^-2, Marangoni number Ma = 0.0 - 6.2067 × 10², Grashof number Gr = 7.1104 × 10⁶, and the aspect ratio As = 1.0 in the Czochralski (CZ) method. The flow state becomes unstable earlier by increasing the absolute value of the thermal coefficient of surface tension in the range of σ_T =0.0 - 1.5 × 10^-5N/mK. Although… More >

K. Kaminishi¹, M. Iino², H. Bessho², M. Taneda³

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.1, pp. 107-110, 2000, DOI:10.3970/cmes.2000.001.107

Abstract An FEA (finite element analysis) program employing a new scheme for crack growth analysis is developed and a prediction method for crack growth life is proposed. The FEA program consists of the subroutines for the automatic element re-generation using the Delaunay Triangulation technique, the element configuration in the near-tip region being provided by a super-element, elasto-inelastic stress analyses, prediction of crack extension path and calculation of fatigue life. The FEA results show that crack extension rate and path are controlled by a maximum opening stress range, Δσ_θmax, at a small radial distance of r = d, where More >