Jiayong Tian^1,2, Ulrich Gabbert², Harald Berger², Xianyue Su¹

CMC-Computers, Materials & Continua, Vol.1, No.4, pp. 327-336, 2004, DOI:10.3970/cmc.2004.001.327

Abstract In this paper, we investigate Lamb wave interaction with delamination in an infinite carbon fiber reinforced plastics (CFRP) laminate by a hybrid method. The infinite CFRP laminate is divided into an exterior zone and an interior zone. In the exterior zone, the wave fields are expressed by wave mode expansion. In the interior zone, the wave fields are modeled by the finite element method (FEM). Considering the continuity condition at the boundary between the exterior and interior zones, the global wave fields can be calculated. Lastly, numerical examples show how a delamination in the laminate More >

S. Tchouikov¹, T. Nishioka¹, T. Fujimoto¹

CMC-Computers, Materials & Continua, Vol.1, No.2, pp. 191-204, 2004, DOI:10.3970/cmc.2004.001.191

Abstract Phenomena of dynamic crack branching are investigated numerically from a macroscopic point of view. Repetitive branching phenomena, interaction of cracks after bifurcation and their stability, bifurcation into two and three branches were the objectives of this research. For the analysis of dynamic crack branching, recently we developed moving finite element method based on Delaunay automatic triangulation [Nishioka, Furutuka, Tchouikov and Fujimoto (2002)]. In this study this method was extended to be applicable for complicated crack branching phenomena, such as bifurcation of the propagating crack into more than two branches, multiple crack bifurcation and so on. More >

Kunigal Shivakumar¹, Anil Bhargava²

CMC-Computers, Materials & Continua, Vol.1, No.2, pp. 173-190, 2004, DOI:10.3970/cmc.2004.001.173

Abstract The fiber optic sensor (FOS) embedded perpendicular to reinforcing fibers causes an `Eye' shaped defect. The length is about 16 times fiber optic radius (R_Fos) and height is about 2R_Fos. The eye contains fiber optics in the center surrounded by an elongated resin pocket. Embedding FOS causes geometric distortion of the reinforcing fiber over a height equal to 6 to 8 R_Fos. This defect causes severe stress concentration at the root of the resin pocket, the interface (in the composite) between the optical fiber and the composite, and at 90° to load direction in the composite. The… More >

John L. Volakis¹, Kubilay Sertel¹, Erik Jørgensen², Rick W. Kindt¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 463-476, 2004, DOI:10.3970/cmes.2004.005.463

Abstract In this paper we address several topics relating to the development and implementation of volume integral and hybrid finite element methods for electromagnetic modeling. Comparisons of volume integral equation formulations with the finite element-boundary integral method are given in terms of accuracy and computing resources. We also discuss preconditioning and parallelization of the multilevel fast multipole method, and propose higher-order basis functions for curvilinear quadrilaterals and volumetric basis functions for curvilinear hexahedra. The latter have the desirable property of vanishing divergence within the element but non-zero curl. In addition, a new domain decomposition is introduced More >

Jin Fa Lee¹, Robert Lee², Fernando Teixeira³

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 423-434, 2004, DOI:10.3970/cmes.2004.005.423

Abstract This paper presents the application of a p-type Multiplicative Schwarz Method (pMUS) for solving three dimensional waveguide discontinuity with arbitrary shapes. The major ingredients of current approach are: a hierarchical curl-conforming basis functions that incorporates an in-exact Helmholtz decomposition; and, treating each polynomial space (or basis functions group) as an abstract grid/domain in the Schwarz method. Various numerical examples are studied using the proposed approach. The performance has been compared to currently available commercial software and demonstrated superior performance in terms of accuracy as well as efficiency. More >

O. Hassan¹, K. Morgan, J. Jones, B. Larwood, N. P. Weatherill

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 383-394, 2004, DOI:10.3970/cmes.2004.005.383

Abstract A numerical procedure for the simulation of 3D problems involving the scattering of electromagnetic waves is presented. As practical problems of interest in this area often involve domains of complex geometrical shape, an unstructured mesh based method is adopted. The solution algorithm employs an explicit finite element procedure for the solution of Maxwell's curl equations in the time domain using unstructured tetrahedral meshes. A PML absorbing layer is added at the artificial far field boundary that is created by the truncation of the physical domain prior to the numerical solution. The complete solution procedure is More >

P. Castillo², J. Koning³, R. Rieben⁴, D. White⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.4, pp. 331-346, 2004, DOI:10.3970/cmes.2004.005.331

Abstract In this article, we present a computational framework for solving problems arising in electromagnetism. The framework is derived from a modern geometrical approach and is based on differential forms (or p-forms). These geometrical entities provide a natural framework for modeling of physical quantities such as electric potentials, electric and magnetic fields, electric and magnetic fluxes, etc. We have implemented an object oriented class library, called FEMSTER. The library is designed for high order finite element approximations. In addition, it can be expanded by including user-defined data types or by deriving new classes. Finally, the versatility More >

H. Okada¹, C. T. Liu², T. Ninomiya¹, Y. Fukui¹, N. Kumazawa¹

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.4, pp. 333-348, 2004, DOI:10.3970/cmes.2004.006.333

Abstract Formulations and applications of an element overlay technique for the mesoscopic analyses of composite structures are presented in this paper. As a zooming technique, the element overlay technique has been applied to various engineering problems. A finite element mesh having finer mesh discretization is superposed at the region to zoom the spatial resolution of analysis. Such a numerical technique is known as the s-version FEM (S-FEM). This paper aims at developing an S-FEM technique that is suited for the mesoscopic analysis of particulate composite materials. Local finite element models that contain the second phase material… More >

Jihan Kim¹, Yong Hyup Kim¹, Sung Won Lee²

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.3, pp. 263-276, 2004, DOI:10.3970/cmes.2004.006.263

Abstract The Koiter's asymptotic method is combined with the assumed strain solid shell element formulation for postbuckling analysis of composite and sandwich structures. The assumed strain solid shell element is free of locking and the small angle assumption, and it allows multiple plies through the element thickness. While laminated composite structures are modeled with single element through the thickness, sandwich structures are modeled with three elements stacked through the thickness to model the face sheets and the core independently. The Koiter's method is used to trace initial postbuckling path. Subsequently, the Koiter's method is switched to More >

M.C. Ho Ba Tho¹

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 489-496, 2003, DOI:10.3970/cmes.2003.004.489

Abstract The objective of the paper is to address the methodology developed to model bone and joints with individualised geometric and material properties from medical image data. An atlas of mechanical properties of human bone has been investigated demonstrating individual differences. From these data, predictive relationships have been established between mechanical properties and quantitative data derived from measurements on medical images. Subsequently, geometric and numerical models of bones with individualised geometrical and mechanical properties have been developed from the same source of image data. The advantages of this modelling technique are its ability to study the More >