K. Han¹, Y. T. Feng¹, D. R. J. Owen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.2, pp. 143-162, 2009, DOI:10.3970/cmes.2009.049.143

Abstract Motivated by Hottel's crossed-string method, this paper presents an accurate algorithm for the evaluation of the geometric view factors in a randomly packed bed of circular particles of various sizes. The radiative heat exchange can thus be predicted accurately. The solution procedure is illustrated and the solution accuracy is assessed via a numerical example. More >

J.M.C.Pereira¹, N.A.R.Maia¹, J.C.F.Pereira¹

CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.2, pp. 113-142, 2009, DOI:10.3970/cmes.2009.049.113

Abstract We present a 2D incompressible Navier-Stokes numerical simulation of a virtual model of an elliptic, or flat plate, foil in hovering flight configuration. Computations obtained with a general purpose solver were validated against reference data on forward flapping flight, normal or dragonfly hovering. The moving mesh technique allows airfoil translation and angular mesh movement accompaining the airfoil stroke motion. Close to the ground the mesh deforms to occupy the narrow computational domain formed between the airfoil and the ground. Computations have been carried out for some parameters, including the distances h between the foil center and… More >

H.Nguyen-Van¹, N.Mai-Duy¹ and T.Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.2, pp. 81-112, 2009, DOI:10.3970/cmes.2009.049.081

Abstract This paper reports the development of a simple and efficient 4-node flat shell element with six degrees of freedom per node for the analysis of arbitrary shell structures. The element is developed by incorporating a strain smoothing technique into a flat shell finite element approach. The membrane part is formulated by applying the smoothing operation on a quadrilateral membrane element using Allman-type interpolation functions with drilling DOFs. The plate-bending component is established by a combination of the smoothed curvature and the substitute shear strain fields. As a result, the bending and a part of membrane More >

A.N. Guz, V.A. Dekret¹

CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.1, pp. 69-80, 2009, DOI:10.3970/cmes.2009.049.069

Abstract The two models in the three-dimensional theory of stability of the nanotube reinforced composite materials are discussed. The model of "infinite fibers" and the model of "short fibers" are considered. The primary objective is attended to "short fibers" model. All results are obtained in the framework of the three-dimensional linearized theory of stability of deformable bodies. More >

I. Emiroglu¹, F. Tasci¹, S. D. Akbarov²

CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.1, pp. 47-68, 2009, DOI:10.3970/cmes.2009.049.047

Abstract The time-harmonic dynamical stress field in the system comprising two axially pre-stressed covering layer and two axially pre-stressed half space was studied under the action of uniformly distributed forces on free face plane of the covering layer. It is assumed that the forces are distributed within the rectangular area. The study was conducted within the scope of the piecewise homogeneous body model with the use of three-dimensional theory of elastic waves in an initially stressed bodies. The materials of the layer and half-space were assumed to be isotropic and homogeneous. The corresponding three-dimensional boundary-value-contact problem… 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 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 More >

K.Willner ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.48, No.3, pp. 303-336, 2009, DOI:10.3970/cmes.2009.048.303

Abstract The dynamic behavior of structures with joints is strongly influenced by the constitutive behavior within the contact areas. In this paper the influence of an elaborate constitutive contact model based on a rough surface model is investigated. The contact model is able to describe several effects like pressure dependent contact stiffness in normal and tangential direction as well as microslip effects. The corresponding constitutive contact laws are implemented in a finite element code. Numerical simulations are compared to experimental results of a clamped double-beam experiment. More >

J. M. García-Aznar^1,2, M. A. Pérez^1,2, P. Moreo^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.48, No.3, pp. 271-302, 2009, DOI:10.3970/cmes.2009.048.271

Abstract There are many interfaces between biological materials with a structural functionality, where their mechanical behaviour is crucial for their own performance. Advanced tools such as cohesive surface models are being used to simulate the failure and degradation of this kind of biological interactions. The goal of this paper, in a first step, is to present some cohesive surface models that include damage and repair in interfaces and its application to different biomechanical problems. Secondly, we discuss about the main challenges that we have to improve in the modelling of interfaces for a mechanobiological approach. More >

M.Galli , M.L.Oyen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.48, No.3, pp. 241-270, 2009, DOI:10.3970/cmes.2009.048.241

Abstract A novel approach is presented for the identification of constitutive parameters of linear poroelastic materials from indentation tests. Load-controlled spherical indentation with a ramp-hold creep profile is considered. The identification approach is based on the normalization of the time-displacement indentation response, in analogy to the well-known one-dimensional consolidation problem. The identification algorithm consists of two nested optimization routines, one in the time-displacement domain and the other in a normalized domain. The procedure is validated by identifying poroelastic parameters from the displacement-time outputs of finite element simulations; the new identification scheme proves both quantitatively reliable and More >