I. Smojver¹, D. Ivancevic¹, D. Mihaljevic²

CMES-Computer Modeling in Engineering & Sciences, Vol.70, No.2, pp. 191-216, 2010, DOI:10.3970/cmes.2010.070.191

Abstract This paper tackles the problem of numerical prediction of bird strike induced damage in real aeronautical structures using highly detailed finite element models and modern numerical approaches. Due to the complexity of today's aeronautical structures, numerical damage prediction methods have to be able to take into account various failure and degradation models of different materials. The work presented in this paper is focused on damage modeling in metallic items of aeronautical structures.
Abaqus/Explicit has been employed to perform geometrical and material nonlinear transient dynamic analyses. The problem of soft body impacts has been tackled by applying a hybrid Eulerian Lagrangian… More >

A.P.S.Selvadurai¹

CMES-Computer Modeling in Engineering & Sciences, Vol.52, No.3, pp. 259-278, 2009, DOI:10.3970/cmes.2009.052.259

Abstract The paper deals with a computational approach for modelling the fragmentation of ice sheets during their impact with stationary structures. The modelling takes into consideration the intact continuum behaviour of the ice as a rate-sensitive elastoplastic material. During impact, the ice sheet can undergo fragmentation, which is controlled by a brittle strength criterion based on the current stress state. The fragmentation allows the generation of discrete elements of the ice sheet, the movements of which are governed by the equations of motion. The contact between individual fragments is governed by a Coulomb criterion. The individual fragments can themselves undergo further… More >

Rade Vignjevic¹, Juan R. Reveles¹, James Campbell¹

CMES-Computer Modeling in Engineering & Sciences, Vol.14, No.3, pp. 181-198, 2006, DOI:10.3970/cmes.2006.014.181

Abstract To correct some of the main shortcomings of conventional SPH, a version of this method based on the Total Lagrangian formalism, T. Rabczuk, T. Belytschko and S. Xiao (2004), is developed. The resulting scheme removes the spatial discretisation instability inherent in conventional SPH, J. Monaghan (1992).
The Total Lagrangian framework is combined with the mixed correction which ensures linear completeness and compliance with the patch test, R. Vignjevic, J. Campbell, L. Libersky (2000). The mixed correction utilizes Shepard Functions in combination with a correction to derivative approximations.
Incompleteness of the kernel support combined with the lack of consistency… 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 >

J. Sladek¹, V. Sladek¹, P. H. Wen², M.H. Aliabadi³

CMES-Computer Modeling in Engineering & Sciences, Vol.13, No.2, pp. 103-118, 2006, DOI:10.3970/cmes.2006.013.103

Abstract A meshless local Petrov-Galerkin (MLPG) method is applied to solve bending problems of shear deformable shallow shells described by the Reissner theory. Both static and dynamic loads are considered. For transient elastodynamic case the Laplace-transform is used to eliminate the time dependence of the field variables. A weak formulation with a unit test function transforms the set of governing equations into local integral equations on local subdomains in the mean surface of the shell. Nodal points are randomly spread on that surface and each node is surrounded by a circular subdomain to which local integral equations are applied. The meshless… More >

A. M. Rajendran¹, D. J. Grove²

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.3, pp. 367-380, 2002, DOI:10.3970/cmes.2002.003.367

Abstract This paper presents detailed computational analyses investigating the ability of constitutive relationships to describe the response of a 99.5% pure alumina (AD995) subjected to a wide range of stress/strain loading states. Using a shock-wave-propagation-based finite element code, one and two-dimensional simulations were performed for the following shock and impact configurations: plate-on-plate impact; rod-on-rod impact; single-density plate-on-rod impact; graded-density plate-on-rod impact; and rod penetration into a thick plate. The detailed analyses presented in this paper include a model constant sensitivity study through comparisons of computed wave profiles with experimental measurements. More >

Byung-Hyuk Lee¹, Se-min Jeong², Sung-Chul Hwang², Jong-Chun Park³, Moo-Hyun Kim⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.91, No.1, pp. 43-63, 2013, DOI:10.3970/cmes.2013.091.043

Abstract The violent free-surface motions interacting with floating vessels containing inner liquid tanks are investigated by using the newly developed Moving Particle Semi-implicit (MPS) method for 2-dimensional incompressible flow simulation. In the present numerical examples, many efficient and robust algorithms have been developed and applied to improve the overall quality and efficiency in solving various highly nonlinear free-surface problems and evaluating impact pressures compared to the original MPS method proposed by Koshizuka and Oka (1996). For illustration, the improved MPS method is applied to the simulation of nonlinear floating-body motions, violent sloshing motions and corresponding impact loads, and vessel motions with… More >

A. Ramachandra Murthy¹ , G.S. Palani¹ , Nagesh R. Iyer¹ , Smitha Gopinath¹ and V. Ramesh Kumar¹

CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.5, pp. 409-434, 2012, DOI:10.3970/cmes.2012.086.409

Abstract This paper presents the details of projectile impact on reinforced concrete structural components. Nonlinear explicit transient dynamic analysis has been carried out by using finite element method. Concrete damage model has been employed to represent the nonlinear behaviour of target under impact load. Various methods of modeling of reinforcement have been explained. A brief note on equation of state for concrete, contact algorithms and nonlinear explicit transient dynamic analysis has been given. Numerical studies have been carried out to compute the response of concrete target due to impact of projectile. The computed penetration depth have been compared with the corresponding… More >

Souli, M.¹, Gabrys, J.²

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.2, pp. 177-192, 2012, DOI:10.3970/cmes.2012.085.177

Abstract Bird impacts on aircraft are very common and cause significant safety threats to commercial and military aircraft. According to FAA ( Federal American Aviation) regulations, aircraft should be able to land safely following specified types of bird impact on components such as radomes, windshields, engines leading edge structures and other exposed components. Thus exposed components are required to be certified for bird impact. In order to evaluate whether the aircraft is compliant to FAA requirements, several experimental tests and numerical simulations of bird impact on components need to be preformed. This paper presents an experimental and numerical investigation of bird… More >

Weiwei Gong, Yan Liu, Xiong Zhang, Honglei Ma

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.5, pp. 527-546, 2012, DOI:10.3970/cmes.2012.083.527

Abstract Owing to its low density and good energy absorption capability, aluminum foam is an excellent protective material for spacecraft against debris impact. However, because of its complicated microstructure, it is very difficult to generate a FEM mesh accounting for the real microstructure of the alluminum foam. On the contrary, it is very easy to model three-dimensional problems with very complicated geometry with meshfree/meshless methods. Furthermore, the material point method has obvious advantages in modeling problems involving extreme large deformation problems like hypervelocity impact problem. In this paper, a three-dimensional material point model accounting for the real microsctructure of aluminum foam… More >