Zhao Huiming¹, Dong Zhengzhu¹, Chen Jiarui¹, Yang Min¹

CMC-Computers, Materials & Continua, Vol.21, No.3, pp. 209-216, 2011, DOI:10.3970/cmc.2011.021.209

Abstract The advantages of coupling of a natural boundary element method and a finite element method are introduced. Then we discuss the principle of the direct coupling of NBEM and FEM and its implementation. The comparison of the results between the direct coupling method and FEM proves that the direct coupling method is simple, feasible and valid in practice. More >

Zhuo-Jia Fu^1,2, Wen Chen¹, Qing-Hua Qin^2,3

CMC-Computers, Materials & Continua, Vol.21, No.3, pp. 187-208, 2011, DOI:10.3970/cmc.2011.021.187

Abstract This paper presents a hybrid finite element model (FEM) with a new type of general solution as interior trial functions, named as HGS-FEM. A variational functional corresponding to the proposed general solution is then constructed for deriving the element stiffness matrix of the proposed element model and the corresponding existence of extremum is verified. Then the assumed intra-element potential field is constructed by a linear combination of novel general solutions at the points on the element boundary under consideration. Furthermore, the independent frame field is introduced to guarantee the intra-element continuity. The present scheme inherits the advantages of hybrid Trefftz… 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 model has been obtained by… More >

S. N.V.R.K. Kurapati¹, Y. C. Lu¹, F. Yang²

CMC-Computers, Materials & Continua, Vol.20, No.1, pp. 1-18, 2010, DOI:10.3970/cmc.2010.020.001

Abstract The spherical indentation of elastic film /substrate structures is analyzed using the finite element method. The load-displacement curves of the film /substrate structures of various configurations are obtained and analyzed. A generalized power law relation is established, which can be used to analyze the load-displacement curve of elastic film /substrate systems under spherical indentations. The indentation load is dependent on the modulus ratio of the film to the substrate and film thickness. A semi-analytical expression for the power of the power law relation is also obtained as a function of the normalized film thickness and normalized film modulus, which can… More >

M. Demiral, A. Roy, V. V. Silberschmidt¹

CMC-Computers, Materials & Continua, Vol.19, No.2, pp. 199-216, 2010, DOI:10.3970/cmc.2010.019.199

Abstract Static indentation experiments are typically performed to characterize the mechanical properties of a material of interest by a rigid indenter of known geometry to various depths. In contrast, dynamic indentation of materials has not been fully studied. Evaluating material performance under dynamic loading conditions is a challenge and we demonstrate that various modelling schemes may be appropriate for different flavours of dynamic indentation. In order to compare underlying thermo-mechanics and deformation processes in a static and dynamic indentation process, indentation of a rigid indenter into a workpiece to a fixed chosen penetration is extensively studied. A nonlinear strain rate and… More >

Lutz Nasdala¹ , Andreas Kempe¹ and Raimund Rolfes¹

CMC-Computers, Materials & Continua, Vol.19, No.1, pp. 57-104, 2010, DOI:10.3970/cmc.2010.019.057

Abstract In order to understand the underlying mechanisms of inelastic material behavior and nonlinear surface interactions, which can be observed on macroscale as damping, softening, fracture, delamination, frictional contact etc., it is necessary to examine the molecular scale. Force fields can be applied to simulate the rearrangement of chemical and physical bonds. However, a simulation of the atomic interactions is very costly so that classical molecular dynamics (MD) is restricted to structures containing a low number of atoms such as carbon nanotubes. The objective of this paper is to show how MD simulations can be integrated into the finite element method… More >

Jun Xu^1,2, Yibing Li¹, Xi Chen^2,3, Yuan Yan^2,3, Dongyun Ge^4,1, Bohan Liu¹

CMC-Computers, Materials & Continua, Vol.18, No.2, pp. 183-212, 2010, DOI:10.3970/cmc.2010.018.183

Abstract The crack pattern in a PVB laminated windshield upon head impact is of considerable interest because it contains important information on energy mitigation, pedestrian protection, and accident reconstruction. We carry out a systematic numerical study based on the extended finite element method (XFEM), to investigate the effects of various material and system variables, including the impact speed, effective head mass, PVB interlayer material thickness and property, windshield curvature, aspect ratio and size, boundary constraint, impact angle and off-center impact, on the parameters characterizing the resulting crack pattern, i.e. the crack length, crack angle and circumferential crack shape. General relations bridging… More >

Fei Jia¹, Xiu-Peng Zheng^1,2, Yan-Ping Cao^1,3, Xi-Qiao Feng¹

CMC-Computers, Materials & Continua, Vol.18, No.2, pp. 105-120, 2010, DOI:10.3970/cmc.2010.018.105

Abstract Recently, a novel technique based on the wrinkling of a bilayer composite film resting on a compliant substrate was proposed to measure the elastic moduli of thin films. In this paper, this technique is studied via theoretical analysis and finite element simulations. We find that under an applied compressive strain, the composite system may exhibit various buckling modes, depending upon the applied compressive strain, geometric and material parameters of the system. The physical mechanisms underlying the occurrence of the two most typical buckling modes are analyzed from the viewpoint of energy. When the intermediate layer is much thicker than the… More >

T.Y. Wu¹, W.C. Tsai², J.J. Lee²

CMC-Computers, Materials & Continua, Vol.17, No.3, pp. 175-214, 2010, DOI:10.3970/cmc.2010.017.175

Abstract The crushing of cellular materials is a highly nonlinear problem, for which geometrical, material, and contact/impact must be treated in one analysis. In order to develop a framework able to solve it efficiently and accurately, in this paper procedures for in-plane crushing analysis of cellular materials using vector form intrinsic finite element (VFIFE) is performed. A beam element of VFIFE is employed to handle large rotation and large deflection in the cell walls. An elastic-plastic material model with mixed hardening rule is adopted to account for material nonlinearity. In addition, an efficient contact/impact algorithm is designed to treat the complex… More >

Taotao Hu¹, gping Shen^1,2

CMC-Computers, Materials & Continua, Vol.17, No.1, pp. 41-58, 2010, DOI:10.3970/cmc.2010.017.041

Abstract In this paper, an axisymmetric indentation model is set up to calculate the effects of the roughness of the thermally grown oxide (TGO) layer, which was modeled as a sinusoidal wave, on the indentation response of the thermal barrier coatings. It is found that the amplitude, wavelength, and thickness of the thermally grown oxide layer have obvious influences on the indentation response, while the effect of the indenter position can be neglected. In the top coating layer, residual stress mainly occurs below the indenter and around the nearest two peaks of the thermally grown oxide layer to the indenter. Only… More >