Li Shan, Ning Cui, Ming Cheng, Kaixin Liu

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.4, pp. 353-384, 2012, DOI:10.3970/cmes.2012.083.353

Abstract In the present paper, a combined scheme of discrete element method (DEM) and meshless method for numerical simulation of impact problems is proposed. Based on the basic principle of continuum mechanics, an axisymmetric DEM framework is established for modeling the elastoplastic behavior of solid materials. Failure criteria are introduced to model the transformation from a continuum to a discontinuum. The friction force between contact elements is also considered after the failure appears. So our scheme can calculate not only the behavior of continuum and discontinuum, but also the transformation process from a continuum to a discontinuum. In addition, a meshless… 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 >

R. Valisetty^1,2, A. Rajendran^1,3, D. Grove²

CMES-Computer Modeling in Engineering & Sciences, Vol.60, No.1, pp. 41-72, 2010, DOI:10.3970/cmes.2010.060.041

Abstract A multi-scale model exhibiting progressive damage is considered for a 3D-woven composite. It is based on the evolution of some fundamental damage modes in a representative volume element (RVE) of a composite's woven architecture. The overall response of a woven composite due to a variety of damage modes is computationally obtained through a transformation field analysis (TFA) that is capable of quantifying the effects of spatial distribution of micro stresses and strains on strength. Since the model is computationally intensive, its numerical requirements are to be understood before it can successfully be used in design studies or in conjunction with… More >

Ji Joong Moon¹, Seung Jo Kim¹, Minhyung Lee²

CMES-Computer Modeling in Engineering & Sciences, Vol.59, No.3, pp. 275-300, 2010, DOI:10.3970/cmes.2010.059.275

Abstract This paper describes the parallelization of contact/impact simulation for fracture modeling of brittle materials using a node separation scheme (NSS). We successfully demonstrated the fracture modeling of brittle materials using a cohesive fracture model. Since a NSS continuously generates new free surfaces as the computation progresses, the methodology requires increased computational time. To perform a simulation within a reasonable time period, a parallelization study is conducted. Particular methods for effective parallelization, especially for brittle materials, are described in detail. The crucial and most difficult strategy is the management of the data structure and communication needed to handle new contact nodes… More >

Baskaran Bhuvaraghan¹, Sivakumar M Srinivasan², Bob Maffeo³, Om Prakash⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.57, No.2, pp. 137-158, 2010, DOI:10.3970/cmes.2010.057.137

Abstract Shot peening is a complex and random process which is controlled by many input parameters. Numerical methods, which are normally used for impact problems will prohibitively put strain on the computing resources since a large number of impacts are involved in the computations. In this paper, a simplified analytical approach is used to predict the residual compressive stress that includes strain-rate effects. This is based on the method proposed by with a simple modification to include the strain rate effects. The residual stresses are predicted in materials SAE1070 and Inco718. In the computations, the random variation of the input parameters… More >

J.T. Zhou¹, Q.W. Ma^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.56, No.2, pp. 179-210, 2010, DOI:10.3970/cmes.2010.056.179

Abstract In this paper, the Meshless Local Petrov-Galerkin method based on Rankine source solution (MLPG_R) is further developed to model 3D breaking waves. For this purpose, the technique for identifying free surface particles called Mixed Particle Number Density and Auxiliary Function Method (MPAM) and the semi-analytical technique for estimating the domain integrals for 2D cases are extended to 3D cases. In addition, a new semi-analytical technique is developed to deal with the local spherical surface integrals. The numerical results obtained by the newly developed method will be compared with experimental data available in literature and satisfactory agreement will be shown. More >

Z. T. Ma¹, X. Zhang^1,2, P. Huang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.55, No.1, pp. 61-88, 2010, DOI:10.3970/cmes.2010.055.061

Abstract The Material Point Method (MPM) is more expensive in terms of storage than other methods, as MPM makes use of both mesh and particle data. Therefore, it is critical to develop an efficient MPM framework for engineering applications, such as impact and explosive simulations. This paper presents a new architecture for MPM computer code, developed using object-oriented design, which enables MPM analysis of a mass of grains, large deformation, high strain rates and complex material behavior. It is flexible, extendible, and easily modified for a variety of MPM analysis procedures. An MPM scheme combining contact algorithm with USF, USL and… More >

LumingShen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.1, pp. 23-46, 2009, DOI:10.3970/cmes.2009.049.023

Abstract A bifurcation-based simulation procedure is proposed in this paper to explore the transition from localization to decohesion involved in the glass fragmentation under impact loading. In the proposed procedure, the onset and orientation of discontinuous failure of glass is identified from the bifurcation analysis based on a rate-dependent tensile damage model. The material point method, which does not involve fixed mesh connectivity, is employed to accommodate the multi-scale discontinuities associated with the fragmentation of glass using a simple interface treatment. A parametric study has been conducted to demonstrate the effects of specimen size and impact velocity on the evolution of… More >

J.C.Campbell¹, R.Vignjevic¹, M.Patel¹, S.Milisavljevic¹

CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.1, pp. 1-22, 2009, DOI:10.3970/cmes.2009.049.001

Abstract This paper presents research towards the development of an analysis technique for predicting the interaction of large ocean waves with ships and offshore structures specifically with respect to the extent of deck submersion, impact loads and the level of structural damage caused. The coupled SPH - Finite Element approach is used, where the water is modeled with SPH and the structure with shell or continuum finite elements. Details of the approach are presented, including the SPH-FE contact and the fluid boundary conditions. Simulation results show that the method can correctly represent the behavior of a floating structure and the structural… More >

A. Djeukou¹, O. von Estorff²

CMES-Computer Modeling in Engineering & Sciences, Vol.47, No.1, pp. 23-42, 2009, DOI:10.3970/cmes.2009.047.023

Abstract The paper deals with the response of rectangular composite plates to low-velocity impact. A third-order shear deformation theory as well as the Newmark integration are used to determine the contact force history analytically. The interaction between the impactor and the plate is modeled with the help of a two degrees-of-freedom system, consisting of springs and masses. The Choi's linearized Hertzian contact model is used to determine the contact force. The maximum impact force is employed for a static damage analysis of the composite plate by means of the radial point interpolation method, while the Tsai-Wu failure criterion is applied for… More >