Lior Banai

CMES-Computer Modeling in Engineering & Sciences, Vol.88, No.5, pp. 351-366, 2012, DOI:10.3970/cmes.2012.088.351

Abstract The explosive Engineering field is a costly one in which not every organization can effort the time and money it takes to performed field tests on its explosives. The purpose of this article is to present a program that was developed in the Israeli Navy for performance estimations and safety issues of warheads and explosives. With a relative small developing time one can create a tool that gives preliminary results in a few minutes without the need to design and order a field tests or run finite elements analyses. By implementing a few known models, in this tool, the user… More >

Z. D. Han¹, H. T. Liu¹, A. M. Rajendran², S. N. Atluri³

CMES-Computer Modeling in Engineering & Sciences, Vol.14, No.2, pp. 119-128, 2006, DOI:10.3970/cmes.2006.014.119

Abstract This paper presents the implementation of a three-dimensional dynamic code, for contact, impact, and penetration mechanics, based on the Meshless Local Petrov-Galerkin (MLPG) approach. In the current implementation, both velocities and velocity-gradients are interpolated independently, and their compatibility is enforced only at nodal points. As a result, the time consuming differentiations of the shape functions at all integration points is avoided, and therefore, the numerical process becomes more stable and efficient. The ability of the MLPG code for solving high-speed contact, impact and penetration problems with large deformations and rotations is demonstrated through several computational simulations, including the Taylor impact… More >

W. Zhang¹, X. Han^1,2, J. Liu¹, R. Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.5, pp. 385-408, 2012, DOI:10.3970/cmes.2012.086.385

Abstract A novel inverse technique is presented for quantifying the uncertainty of the identified the results in an encounter condition identification problem. In this technique, the polynomial response surface method based on the structure-selection technique is first adopted to construct the approximation model of the projectile/target system, so as to reduce the computational cost. The Markov Chain Monte Carlo method is then used to identify the encounter condition parameters and their confidence intervals based on this cheap approximation model with Bayesian perspective. The results are demonstrated through the simulated test cases, which show the utility and efficiency of the proposed technique.… More >

Qiang Li¹, Jie Ouyang¹, Guorong Wu¹, Xiaoyang Xu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.82, No.3&4, pp. 215-232, 2011, DOI:10.32604/cmes.2011.082.215

Abstract The governing equations of two-phase flows including gas and polymer melt are presented, which are solved using finite volume and domain extension methods with SIMPLEC technology. The melt filling and primary gas penetration in gas-assisted injection molding (GAIM) process are simulated, where the Cross-viscosity model is employed to describe the melt rheological behavior, and the CLSVOF(coupled Level Set and Volume of fluid) method is employed to capture the moving interfaces. In order to test and verify the coupled methods, melt filling in a rectangular plate with an insert is simulated, and the numerical results are in good agreement with those… More >

Kun Luan¹, Baozhong Sun¹, Bohong Gu^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.79, No.1, pp. 31-62, 2011, DOI:10.3970/cmes.2011.079.031

Abstract This paper reports finite element multi-scale simulations of ballistic impact damage of three-dimensional angle-interlock woven composite (3DAWC) penetrated under a hemispherical rigid projectile. A multi-scale geometrical model of the 3DAWC was established for the numerical simulation. The multi-scale geometrical model of the 3DAWC consists two parts: one is the microstructure model and another is the continuum model. The microstructure model has the same microstructure with that of the 3DAWC composite panel, including the fiber tows' diameter, fiber tow configuration and fiber volume fraction. The continuum model has the same mechanical properties with the 3DAWC. The commercial-available finite element software package… More >

Huamin Zhou¹, Hua Zhang, Dequn Li²

CMES-Computer Modeling in Engineering & Sciences, Vol.46, No.3, pp. 209-220, 2009, DOI:10.3970/cmes.2009.046.209

Abstract Gas-assisted injection molding is an innovative process to manufacture hollow polymeric products, in which gas penetration is the primary and key problem. An analytical solution of the gas penetration interface is presented, based on perturbation method. First, the governing equations and boundary conditions are transformed to be dimensionless, where Capillary number Ca is introduced. Then matching asymptotic expansion method is applied to solve these equations, by using Ca and as perturbation parameters to get the inner and outer solutions, respectively. By matching these two solutions, the analytical model of gas penetration is obtained. More >

L. Wang¹, S. Zhang, W. M. Gao, X. Wang

CMES-Computer Modeling in Engineering & Sciences, Vol.20, No.1, pp. 11-20, 2007, DOI:10.3970/cmes.2007.020.011

Abstract In this paper, the penetration of a knife through a plain woven fabric is simulated with the finite element method to understand the process of stabbing and the mechanism of fiber breakage. The model focuses on the study of the deformation of individual yarns, and the effects of their material properties and fabric structure on the stabbing resistant force. The performance of the fabric is analyzed as a response of stabbing and the stress distributions in yarn transverse and longitudinal directions. An equation derived from energy and momentum conservations of the knife is proposed to predict the depth of the… More >

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 >

H. T. Liu¹, Z. D. Han¹, A. M. Rajendran², S. N. Atluri³

CMC-Computers, Materials & Continua, Vol.4, No.1, pp. 43-54, 2006, DOI:10.3970/cmc.2006.004.043

Abstract The Rajendran-Grove (RG) ceramic damage model is a three-dimensional internal variable based constitutive model for ceramic materials, with the considerations of micro-crack extension and void collapse. In the present paper, the RG ceramic model is implemented into the newly developed computational framework based on the Meshless Local Petrov-Galerkin (MLPG) method, for solving high-speed impact and penetration problems. The ability of the RG model to describe the internal damage evolution and the effective material response is investigated. Several numerical examples are presented, including the rod-on-rod impact, plate-on-plate impact, and ballistic penetration. The computational results are compared with available experiments, as well… More >