J. Badur¹, M. Karcz¹, M. Lemanski¹, L. Nastalek¹

CMES-Computer Modeling in Engineering & Sciences, Vol.73, No.3, pp. 299-310, 2011, DOI:10.3970/cmes.2011.073.299

Abstract In the paper we propose to remove the classical Navier slip condition and replace it with new generalized Navier-Stokes slip boundary conditions. These conditions are postulated to be ones following from the mass and momentum balance within a thin, shell-like moving boundary layer. Owing to this, the problem consistency between the internal and external friction in a viscous fluid is solved within the framework of a proper form of the layer balances, and a proper form of constitutive relations for appropriate friction forces. Finally, the common features of the Navier, Stokes, Maxwell and Reynolds concepts More >

Ping Hu¹, Yang Xia¹, Limin Tang²

CMES-Computer Modeling in Engineering & Sciences, Vol.73, No.2, pp. 103-136, 2011, DOI:10.3970/cmes.2011.073.103

Abstract In this paper, an assumed displacement quasi-conforming finite element method with truncated polynomial expansions of in-domain displacements and derived expansions of strains is introduced. Based on the method a four-node quadrilateral flat shell element with complete quadratic polynomials for membrane and bending displacement fields is developed. Numerical tests are carried out for validation of the present element. The results show that the present element preserves all the advantages of the quasi-conforming i.e., explicit stiffness matrix, convenient post processing and free from membrane locking and shear locking. The tests also prove that the present element gives More >

H. T. Wang^1,2, Z. H. Yao³

CMES-Computer Modeling in Engineering & Sciences, Vol.72, No.2, pp. 115-148, 2011, DOI:10.3970/cmes.2011.072.115

Abstract A fast boundary element solver for the analysis of three-dimensional general crack problems is presented. In order to effectively model the embedded or edge cracked structures a dual boundary integral equation (BIE) formulation is used. By implementing the fast multipole method (FMM) to the discretized BIE, structures containing a large number of three-dimensional cracks can be readily simulated on one personal computer. In the FMM framework, a multipole expansion formulation is derived for the hyper-singular integral in order that the multipole moments of the dual BIEs containing the weakly-, strongly- and hyper-singular kernels are collected More >

Leonard G. Gomella

Canadian Journal of Urology, Vol.17, No.5, pp. 5343-5343, 2010

Abstract This article has no abstract. More >

Mark Pompetzki¹, Brian Dabell¹, Xiaobin Lin²

Structural Durability & Health Monitoring, Vol.6, No.2, pp. 69-76, 2010, DOI:10.3970/sdhm.2010.006.069

Abstract Structural integrity in terms of automotive durability is a detailed process that incorporates many technical areas. The current durability process for automotive applications involves understanding operational load inputs, the stresses and strains caused and the response of the material, performing fatigue tests, calculating fatigue life and interpreting results. There are many variations on this process depending on the application, materials, available information, methods, etc. This paper presents a general approach for the durability process in automotive applications and highlights a number of new advancements. These advancements include understanding the service operating load conditions through improved More >

Y.C. Shiah¹, C. L. Tan², R.F. Lee¹

CMES-Computer Modeling in Engineering & Sciences, Vol.69, No.2, pp. 167-198, 2010, DOI:10.3970/cmes.2010.069.167

Abstract In this paper, fully explicit, algebraic expressions are derived for the first and second derivatives of the Green's function for the displacements in a three dimensional anisotropic, linear elastic body. These quantities are required in the direct formulation of the boundary element method (BEM) for determining the stresses at internal points in the body. To the authors' knowledge, similar quantities have never previously been presented in the literature because of their mathematical complexity. Although the BEM is a boundary solution numerical technique, solutions for the displacements and stresses at internal points are sometimes required for More >

E. Carrera, S. Brischetto¹, M. Cinefra²

CMES-Computer Modeling in Engineering & Sciences, Vol.65, No.3, pp. 259-342, 2010, DOI:10.3970/cmes.2010.065.259

Abstract This paper investigates the problem of free vibrations of multilayered plates and shells embedding anisotropic and thickness polarized piezoelectric layers. Carrera's Unified Formulation (CUF) has been employed to implement a large variety of electro-mechanical plate/shell theories. So-called Equivalent Single Layer and Layer Wise variable descriptions are employed for mechanical and electrical variables;linear to fourth order expansions are used in the thickness direction z in terms of power of z or Legendre polynomials. Various forms are considered for the Principle of Virtual Displacements (PVD) and Reissner's Mixed Variational Theorem (RMVT) to derive consistent differential electro-mechanical governing… More >

Ching Kong Chao^1,2, Chin Kun Chen¹, Fu Mo Chen³

CMES-Computer Modeling in Engineering & Sciences, Vol.63, No.1, pp. 1-28, 2010, DOI:10.3970/cmes.2010.063.001

Abstract A general analytical solution for a reinforced elliptical hole embedded in an infinite matrix subjected to a point heat source is provided in this paper. Based on the technique of conformal mapping and the method of analytical continuation in conjunction with the alternating technique, the general expressions of the temperature and stresses in the reinforcement layer and the matrix are derived explicitly in a series form. Some numerical results are provided to investigate the effects of the material combinations and geometric configurations on the interfacial stresses. The solution obtained can be treated as Green's functions More >

B.Y. Lee¹, Y. Lee², J.K.Kim³, Y.Y.Kim⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.61, No.2, pp. 111-132, 2010, DOI:10.3970/cmes.2010.061.111

Abstract In the present work, a micromechanics-based fiber-bridging constitutive model that quantitatively takes into consideration the distribution of fiber orientation and the number of fibers, is derived and a fiber-bridging analysis program is developed. An image processing technique is applied to evaluate the fiber distribution characteristics of four different types of strain-hardening cementitious composites. Then, the fiber-bridging curves obtained from image analysis are compared with those obtained from the assumption of two- and three-dimensional fiber distributions. The calculated ultimate tensile strains are also compared with experimental results. Test results showed that the tensile behavior of strain-hardening More >

S. Ullah¹, B. Pichler¹, S. Scheiner^1,2, C. Hellmich^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.57, No.3, pp. 279-316, 2010, DOI:10.3970/cmes.2010.057.279

Abstract Point-wise optical measurements of 3D displacement vectors over time are a key input for monitoring shotcrete tunnel shells during construction according to the New Austrian Tunnelling Method (NATM). Aiming at estimation of the stresses prevailing in the highly loaded, hydrating material, we here deal with two different interpolation strategies for reconstructing, from measured displacement vectors, the 3D displacement field histories of the inner surface of the tunnel shell. The first approach considers spatial interpolation of displacement components in a fixed Cartesian base frame, while the second (new) approach refers to displacement components in a moving… More >