X.-H. Chen¹, Y.-W. Mai²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.14, No.2, pp. 43-50, 2010, DOI:10.3970/icces.2010.014.043

Abstract A general elastoplastic fracture mechanics theory is proposed for applying the Essential-Work-of-Fracture (EWF) Method to quasi-static and impact toughness characterization. Advanced finite element modeling is developed to simulate the EWF Method using the crack-tip opening angle criterion (CTOA) and the constitutive relation of the material under consideration. For Poly(ethylene-terephlate) (PET) films, the load-displacement curves are calculated for the whole crack propagation process of deeply double-edge notched tensile specimens (DENT) with different ligament lengths so as to determine the total work, the essential work and the non-essential work of fracture. The effects of specimen gauge length More >

D. Kakogiannis¹, D. Van Hemelrijck¹, J. Wastiels¹, S. Palanivelu², W. Van Paepegem², J. Vantomme³, A. Kotzakolios⁴, V. Kostopoulos⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.65, No.1, pp. 75-94, 2010, DOI:10.3970/cmes.2010.065.075

Abstract In the present study the estimation of the blast wave by two types of finite element methods is investigated: Eulerian multi-material modeling and pure Lagrangian. The main goal is to compare and study their ability to predict the clearing effect during blast. Element shape and improvements on the codes are also considered. For the Lagrangian finite element models the load is applied by using an empirical method, deriving from databases, for the time-spatial distribution of the pressure profiles. In the ideal case of the above method the blast load is applied as an equivalent triangular… More >

Y. Inoue¹, R. Kobayashi¹, S. Ogata¹, T. Gotoh¹

CMES-Computer Modeling in Engineering & Sciences, Vol.63, No.2, pp. 137-162, 2010, DOI:10.3970/cmes.2010.063.137

Abstract Vibration of a single graphene and a pair of graphenes at micro meter scale induced by air flow is numerically simulated and examined by using a hybrid computational method starting from a microscopic level of description for the graphene. In order to bridge a huge gap in spatial and time scales in their motions, the carbon atoms of the graphene are represented by a small number of coarse grained particles, the fluid motion is described by the lattice Boltzmann equation and the momentum exchange at the boundary is treated by the time averaged immersed boundary… More >

F.P. Mariano¹, L.Q. Moreira¹, A. Silveira-Neto¹, C.B. da Silva², J.C.F. Pereira²

CMES-Computer Modeling in Engineering & Sciences, Vol.59, No.2, pp. 181-216, 2010, DOI:10.3970/cmes.2010.059.181

Abstract A new numerical methodology combining Fourier pseudo-spectral and immersed boundary methods - IMERSPEC - is developed for fluid flow problems governed by the incompressible Navier-Stokes equations. The numerical algorithm consists in a classical Fourier pseudo-spectral methodology using the collocation method where wall boundary conditions are modelled by using an immersed boundary method (IBM). The performance of that new methodology is exemplified in two-dimensional numerical simulations of Green-Taylor decaying vortex, lid-driven cavity and flow over a square cylinder. The convergence rate, the accuracy, the influence of the Reynolds number and the external domain size are analyzed. More >

Y. T. Gu¹, P. Zhuang², F. Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.56, No.3, pp. 303-334, 2010, DOI:10.3970/cmes.2010.056.303

Abstract Recently, the numerical modelling and simulation for anomalous subdiffusion equation (ASDE), which is a type of fractional partial differential equation(FPDE) and has been found with widely applications in modern engineering and sciences, are attracting more and more attentions. The current dominant numerical method for modelling ASDE is Finite Difference Method (FDM), which is based on a pre-defined grid leading to inherited issues or shortcomings. This paper aims to develop an implicit meshless approach based on the radial basis functions (RBF) for numerical simulation of the non-linear ASDE. The discrete system of equations is obtained by… More >

X. H. Du¹, X. P. Shen¹

CMC-Computers, Materials & Continua, Vol.20, No.3, pp. 225-242, 2010, DOI:10.3970/cmc.2010.020.225

Abstract Aim of this paper is to estimate the integrity of liquefied natural gas (LNG) prestressed storage tank under seismic influence. The coupled Eulerian-Lagrangian (CEL) analysis technique is used to simulate the fluid-structure interaction between LNG and the cylinder of LNG prestressed storage tank. The 3-D model of LNG has been dispersed by Eulerian mesh that is different from traditional analysis method which is called the added mass method. Meanwhile, both of the 3-D models of prestressed rebar and concrete structure are dispersed by Lagrangian mesh. Following conclusions are obtained: 1) Natural frequency of the whole… More >

Alamusi¹, Y.L. Liu¹, N. Hu^1,2

CMC-Computers, Materials & Continua, Vol.20, No.2, pp. 101-118, 2010, DOI:10.3970/cmc.2010.020.101

Abstract In this work, we propose a 3 dimensional (3D) numerical model to predict the piezoresistivity behaviors of a nanocomposite material made from an insulating polymer filled by carbon nanotubes (CNTs). This material is very hopeful for its application in highly sensitive strain sensor by measuring its piezoresistivity, i.e., the ratio of resistance change versus applied strain. In this numerical approach, a 3D resistor network model is firstly proposed to predict the electrical conductivity of the nanocomposite with a large amount of randomly dispersed CNTs under the zero strain state. By focusing on the fact that… More >

Chen Y J^1,2, Huber N^2,3

CMC-Computers, Materials & Continua, Vol.16, No.1, pp. 1-24, 2010, DOI:10.3970/cmc.2010.016.001

Abstract An efficient wear integration algorithm is crucial for the simulation of wear in complex transient contact situations. By rewriting Archard's wear law for two dimensional problems, the wear integration can be replaced by the total contact force. This avoids highly resolved simulations in time and space, so that the proposed method allows a significant acceleration of wear simulations. All quantities, including the average contact velocity, slip rate and total contact force, which are required for the pressure-force transformation, can be determined from geometric and motion analysis, or alternatively, from Finite Element simulations. The proposed CForce More >

Ch.Raghuveer¹, Mohit Pant¹, I.V. Singh¹, B.K. Mishra¹, V. Bhasin², Kamal Sharma², I.A. Khan²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.1, pp. 23-32, 2009, DOI:10.3970/icces.2009.012.023

Abstract In this work, element free Galerkin method (EFGM) has been applied to solve solid mechanics problems containing material discontinuities. The method is based on treatment of interface conditions at the variational level. Modifications are made in the EFGM to incorporate material discontinuities, which include the variational form of the governing differential equations. Two bi-material problems i.e. beam and bar has been solved using EFGM, and a clear discontinuity in the stress field has been observed at the interface of two materials. More >

Keerasut Suttanarak¹, Nirut Naksuk², Jarruwat Charoensuk¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 87-88, 2009, DOI:10.3970/icces.2009.010.087

Abstract The water management in Proton Exchange Membrane (PEMFC) is crucial in operating PEMFC system concerning water balance between electrode and membrane. Improper cell humidification might lead to drying or flooding of the electrodes, which degrades cell performance. In this research, effects of gas humidification are studied to aid a system designer in achieving the optimal condition of fuel cell system. The investigation takes into account the conservation of mass, momentum, energy and species as well as the water transport equations including electro-osmotic drag and back diffusion through numerical simulation. More >