Xianhui Wang¹, Jianming Zhang^1,2, Xingshuai Zheng¹, Fenglin Zhou¹

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.1, pp. 69-90, 2013, DOI:10.3970/cmes.2013.093.069

Abstract In this paper, a half space adaptive fast multipole boundary face method (FMBFM) is presented for solving the three-dimensional half space exterior acoustic problems. In the presented method, the Burton-Miller equation based on the conventional boundary integral equation (CBIE) and its hyper-singular boundary integral equation (HBIE) is used to deal with the fictitious eigenfrequencies problem. The half space Green’s function is employed, thus the tree structure in the fast multipole method can be used only for the real domain. The higher order elements and an adaptive tree structure are used to improve the efficiency of the FMBFM. This half space… More >

Jin Li¹, De-hao Yu^{2, 3}

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.1, pp. 47-67, 2013, DOI:10.3970/cmes.2013.093.047

Abstract The composite classical trapezoidal rule for the computation of Cauchy principal value integral with the singular kernel 1/(x-s) is discussed. Based on the investigation of the superconvergence phenomenon, i.e., when the singular point coincides with some priori known point, the convergence rate of the classical trapezoidal rule is higher than the globally one which is the same as the Riemann integral for classical trapezoidal rule. The superconvergence phenomenon of the composite classical trapezoidal rule occurs at certain local coordinate of each subinterval and the corresponding superconvergence error estimate is obtained. Some numerical examples are provided to validate the theoretical analysis. More >

Y.M. Wang^1,2, Q. Wu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.1, pp. 17-45, 2013, DOI:10.3970/cmes.2013.093.017

Abstract A new kind of operator-orthogonal wavelet-based element is constructed based on the lifting scheme for adaptive analysis of thin plate bending problems. The operators of rectangular and skew thin plate bending problems and the sufficient condition for the operator-orthogonality of multilevel stiffness matrix are derived in the multiresolution finite element space. A new type of operator-orthogonal wavelets for thin plate bending problems is custom designed with high vanishing moments to be orthogonal with the scaling functions with respect to the operators of the problems, which ensures the independent solution of the problems in each scale. An adaptive operator-orthogonal wavelet method… More >

Lijun Xue¹, Guansuo Dui^1,2, Bingfei Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.1, pp. 1-16, 2013, DOI:10.3970/cmes.2013.093.001

Abstract The Functionally Graded Shape Memory Alloy (FG-SMA) is a new kind of functional materials which possesses the excellent properties of both Shape Memory Alloy (SMA) and Functionally Graded Material (FGM). A macro constitutive model of FG-SMA is established by using the theory of the mechanics of composites and the existing SMA model. With this macro constitutive model, the mechanical behavior of a FG-SMA beam composed by elastic material A and SMA subjected to pure bending is investigated. The loading processes including elastic process and phase transformation process are discussed in detail and the analytical solutions are obtained. What is more,… More >

A.V. Ekhlakov^1,2, O.M. Khay^1,3, Ch. Zhang¹, X.W. Gao⁴, J. Sladek⁵, V. Sladek⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.6, pp. 595-614, 2013, DOI:10.3970/cmes.2013.092.595

Abstract A boundary-domain integral equation method is applied to the transient thermoelastic crack analysis in functionally graded materials. Fundamental solutions for homogeneous, isotropic and linear elastic materials are used to derive the boundary-domain integral equations. The radial integration method, the Cartesian transformation method and the cell-integration method are applied for the evaluation of the arising domain-integrals. Numerical results for dynamic stress intensity factors obtained by the three approaches are presented, compared and discussed to show the accuracy and the efficiency of the domain-integral evaluation techniques. More >

De-Shin Liu¹, Chin-Yi Tu¹, Cho-Liang Chung²

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.6, pp. 573-594, 2013, DOI:10.3970/cmes.2013.092.573

Abstract The Infinite Element Method (IEM) is widely used for the analysis of elastostatic structures containing singularities. In the IEM method, the problem domain is partitioned into multiple element layers, where the stiffness matrix of each layer is similar to that of the other layers in the discretized domain. However, in Mindlin-Reissner plate theory, the stiffness matrix varies through the layers of the plate, and thus the conventional IEM algorithm cannot be applied. Accordingly, the present study proposes a Plate Infinite Element Method (PIEM) in which the element stiffness matrix is separated into two sub-matrices; each being similar to the equivalent… More >

Zhao Xilong¹, Zhang Jianxun¹, Chen Hongyuan^1,2, Song Xu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.6, pp. 557-571, 2013, DOI:10.3970/cmes.2013.092.557

Abstract In order to study failure perspective of Ti-6Al-4V titanium alloy welded joint, fracture behavior of the heat affected zone is researched. Microhardness, tensile test and microstructure are used to study the mechanical properties of the titanium alloy laser welded joint. The tensile and microhardness results show that heat affected zone near the base metal is the weakest in welded joints. This paper is based on the results from in-situ tension test to observe the process of crack expansion in heat affected zone. And then, in-situ test is simulated via the finite element method on ABAQUS Standard; therefore the fracture criteria… More >

X. X. Cui¹, X. Zhang^1,2, K. Y. Sze³, X. Zhou⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.5, pp. 507-538, 2013, DOI:10.3970/cmes.2013.092.507

Abstract Based on the material point method (MPM), an alternating finite difference material point (AFDMP) method is proposed for modeling the 3D high explosive (HE) explosion and its interaction with structures nearby. The initiatory detonation and eventual fluid structure interaction (FSI) are simulated by the standard MPM. On the other hand, the finite difference method (FDM) is employed to simulate the dispersion of the detonation products into the surrounding air where the particles degenerate to marker points which track the moving interface between detonation products and air. The conversion between MPM and FDM is implemented by the projection between the particles… More >

Xiaojing Liu¹, Jizeng Wang^1,2, Youhe Zhou^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.5, pp. 493-505, 2013, DOI:10.3970/cmes.2013.092.493

Abstract By combining techniques of boundary extension and Coiflet-type wavelet expansion, an approximation scheme for a function defined on a two-dimensional bounded space is proposed. In this wavelet approximation, each expansion coefficient can be directly obtained by a single-point sampling of the function. And the boundary values and derivatives of the bounded function can be embedded in the modified wavelet basis. Based on this approximation scheme, a modified wavelet Galerkin method is developed for solving two-dimensional nonlinear boundary value problems, in which the interpolating property makes the solution of such strong nonlinear problems very effective and accurate. As an example, we… More >

Yonghua Zhou¹, Xun Yang¹, Chao Mi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.5, pp. 477-491, 2013, DOI:10.3970/cmes.2013.092.477

Abstract Route selections for vehicles can be equivalent to determine the optimized operation processes for vehicles which intertwine with each other. This paper attempts to utilize the whole methodology of model predictive control to engender rational routes for vehicles, which involves three important parts, i.e. simulation prediction, rolling optimization and feedback adjustment. The route decisions are implemented over the rolling prediction horizon taking the real-time feedback information and the future intertwined operation processes into account. The driving behaviors and route selection speculations of drivers and even traffic propagation models are on-line identified and adapted for the simulation prediction in next prediction… More >