Ankush Aggarwal¹, Jiun-Shyan Chen², William S. Klug³

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.1, pp. 69-99, 2014, DOI:10.3970/cmes.2014.098.069

Abstract Mechanical properties of proteins play an important role in their biological function. For example, microtubules carry large loads to transport organelles inside the cell, and virus shells undergo changes in shape and mechanical properties during maturation which affect their infectivity. Various theoretical models including continuum elasticity have been applied to study these structural properties, and a significant success has been achieved. But, the previous frameworks lack a connection between the atomic and continuum descriptions. Here this is accomplished through the development of a meshfree framework based on reproducing kernel shape functions for the large deformation mechanics of protein structures. The… More >

N Pimprikar¹, J Teresa², D Roy^1,3, R M Vasu⁴, K Rajan⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.1, pp. 33-61, 2013, DOI:10.3970/cmes.2013.092.033

Abstract Nearly pollution-free solutions of the Helmholtz equation for k-values corresponding to visible light are demonstrated and verified through experimentally measured forward scattered intensity from an optical fiber. Numerically accurate solutions are, in particular, obtained through a novel reformulation of the H1 optimal Petrov-Galerkin weak form of the Helmholtz equation. Specifically, within a globally smooth polynomial reproducing framework, the compact and smooth test functions are so designed that their normal derivatives are zero everywhere on the local boundaries of their compact supports. This circumvents the need for a priori knowledge of the true solution on the support boundary and relieves the… More >

M. Khezri¹, Z. Vrcelj¹, M.A. Bradford^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.4, pp. 271-306, 2012, DOI:10.3970/cmes.2012.087.271

Abstract A finite strip method (FSM) utilising the generalised reproducing kernel particle method (RKPM) [Behzadan, Shodja, and Khezri (2011)] is developed for the bending analysis of thin plates. In this innovative approach, the spline functions in the conventional spline finite strip method (SFSM) are replaced with generalised RKPM 1-D shape functions in the longitudinal direction, while the transverse cubic functions which are used in the conventional formulations are retained. Since the generalised RKPM is one of the class of meshfree methods which deal efficiently with derivative-type essential boundary conditions, its introduction in the FSM is beneficial for solving boundary value problems… More >

Timon Rabczuk¹, Pedro Areias²

CMES-Computer Modeling in Engineering & Sciences, Vol.16, No.2, pp. 115-130, 2006, DOI:10.3970/cmes.2006.016.115

Abstract This paper proposes a meshfree method for arbitrary evolving cracks in thin shells. The approach is an improvement of the method proposed by Rabczuk T., Areias P.M.A., Belytschko T. (A meshfree thin shell for large deformation, finite strain and arbitrary evolving cracks, International Journal for Numerical Methods in Engineering). In the above cited paper, a shell was developed based on an intrinsic basis of third order completeness. Third order completeness was necessary to remove membrane locking. This resulted in the use of very large domains of influence that made the method computationally expensive. If the crack was modelled by a… More >

S. Masuda¹, H. Noguchi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.3, pp. 131-144, 2006, DOI:10.3970/cmes.2006.011.131

Abstract This paper presents a novel and accurate technique for modeling discontinuous derivatives in meshfree methods, which will be used in the analysis of structures with material interfaces. The novelty lies in the formulation of the Moving Least Squares Approximation (MLSA) scheme where an introduced discontinuous derivative basis function replaces the conventional linear basis function. Furthermore, it is easy to implement this novelty into existing meshfree methods, such as the Element Free Galerkin (EFG) method, which are based on the MLSA scheme. The successful analyses of one and two-dimensional structures with material interfaces demonstrate the potential of the proposed technique. More >

G. C. Bourantas¹, V. C. Loukopoulos²

CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.4, pp. 275-300, 2012, DOI:10.3970/cmes.2012.086.275

Abstract This paper formulates a local Radial Basis Functions (LRBFs) collocation method for the numerical solution of the non-linear dispersive and dissipative KdV-Burger's (KdVB) equation. This equation models physical problems, such as irrotational incompressible flow, considering a shallow layer of an inviscid fluid moving under the influence of gravity and the motion of solitary waves. The local type of approximations used, leads to sparse algebraic systems that can be solved efficiently. The Inverse Multiquadrics (IMQ), Gaussian (GA) and Multiquadrics (MQ) Radial Basis Functions (RBF) interpolation are employed for the construction of the shape functions. Accuracy of the method is assessed in… More >

Mehdi Tatari¹, Maryam Kamranian², Mehdi Dehghan²

CMES-Computer Modeling in Engineering & Sciences, Vol.82, No.1, pp. 1-28, 2011, DOI:10.32604/cmes.2011.082.001

Abstract In this paper, the finite point method (FPM) is presented for solving nonlinear reaction-diffusion systems which are often employed in mathematical modeling in developmental biology. In order to avoid directly solving a coupled nonlinear system, a predicator-corrector scheme is applied. The finite point method is a truly meshfree technique based on the combination of the moving least squares approximation on a cloud of points with the point collocation method to discretize the governing equations. The lack of dependence on a mesh or integration procedure is an important feature, which makes the FPM simple, efficient and applicable to solve nonlinear problems… More >

B. Ren^1,2, J. Qian¹, X. Zeng¹, A. K. Jha³, S. Xiao⁴, S. Li^1,5

CMES-Computer Modeling in Engineering & Sciences, Vol.71, No.3, pp. 253-278, 2011, DOI:10.3970/cmes.2011.071.253

Abstract Ductile failure is a complex multi-scale phenomenon evolved from the micro-voids to macro-crack. There are three main failure mechanisms behinds a ductile failure: adiabatic shear band (ASB), spall fracture, and crack. Since this type of thermo-mechanical phenomena involves large deformation and large scale plastic yielding, a meshfree method has intrinsic advantages in solving this kind of problems over the conventional finite element method. In this paper, the numerical methodologies including multi-physics approach for ASB, parametric visibility condition for crack propagation, and multi-scale approach to determine spall strength in simulating ductile failure have been reviewed. A thermo-mechanical coupling algorithm is proposed… More >

Dongdong Wang^1,2, Yue Sun², Ling Li²

CMES-Computer Modeling in Engineering & Sciences, Vol.45, No.1, pp. 57-82, 2009, DOI:10.3970/cmes.2009.045.057

Abstract A discontinuous Galerkin meshfree formulation is proposed to solve the potential and elasticity problems of composite material where the material interface has to be appropriately modeled. In the present approach the problem domain is partitioned into patches or sub-domains and each patch holds the same material properties. The discretized meshfree particles within a patch are classified as one particle group. Various patches occupied by different particle groups are then linked using the discontinuous Galerkin formulation where an averaged interface flux or traction is constructed based on the fluxes or tractions computed from the adjacent patches. The gradient jump condition across… More >

L.M.J.S. Dinis¹, R.M. Natal Jorge², J. Belinha³

CMES-Computer Modeling in Engineering & Sciences, Vol.44, No.1, pp. 1-34, 2009, DOI:10.3970/cmes.2009.044.001

Abstract The Natural Neighbour Radial Point Interpolation Method (NNRPIM) is extended to the large deformation analysis of non-linear elastic structures. The nodal connectivity in the NNRPIM is enforced using the Natural Neighbour concept. After the Voronoï diagram construction of the unstructured nodal mesh, which discretize the problem domain, small cells are created, the "influence-cells". These cells are in fact influence-domains entirely nodal dependent. The Delaunay triangles are used to create a node-depending background mesh used in the numerical integration of the NNRPIM interpolation functions. The NNRPIM interpolation functions, used in the Galerkin weak form, are constructed with the Radial Point Interpolators.… More >