Chih-Ping Wu, Jyh-Yeuan Lo, Jyh-Ka Chao¹

CMC-Computers, Materials & Continua, Vol.2, No.2, pp. 119-138, 2005, DOI:10.3970/cmc.2005.002.119

Abstract An asymptotic theory of doubly curved laminated piezoelectric shells is developed on the basis of three-dimensional (3D) linear piezoelectricity. The twenty-two basic equations of 3D piezoelectricity are firstly reduced to eight differential equations in terms of eight primary variables of elastic and electric fields. By means of nondimensionalization, asymptotic expansion and successive integration, we can obtain recurrent sets of governing equations for various order problems. The two-dimensional equations in the classical laminated piezoelectric shell theory (CST) are derived as a first-order approximation to the 3D piezoelectricity. Higher-order corrections as well as the first-order solution can be determined by treating the… More >

S.K. Pal¹, D.A. Linkens²

CMC-Computers, Materials & Continua, Vol.2, No.2, pp. 113-118, 2005, DOI:10.3970/cmc.2005.002.113

Abstract In hot rolling, the final thickness of the strip is achieved through plastic deformation of the original stock by a series of counter-rotating rollers. In this work, static recrystallization kinetics in between two stages of steel rolling has been modelled, and simulation studies have also been performed to find out the effect of entry temperature on the recrystallization kinetics. A viable bond graph model has been developed to study the kinetics of the process. Low-carbon steel has been considered for this purpose. More >

Tong-qing Guo, Zhi-liang Lu¹

CMC-Computers, Materials & Continua, Vol.2, No.2, pp. 105-112, 2005, DOI:10.3970/cmc.2005.002.105

Abstract In this paper, a rapid deforming technique is developed to generate dynamic, three-dimensional, multi-block, mesh. The second-order Runge-Kutta time-marching method is used to solve the structural equations of motion. A dual-time method and finite volume discretization are applied for the unsteady Euler/Navier-Stokes equations to calculate the aerodynamic forces, in which the physical time step is synchronous with the structural equations of motion. The Spalart-Allmaras turbulence model is adopted for a turbulent flow. Due to mass dissimilarity, exiting in flutter calculations for a compressible flow, methods of variable mass and variable stiffness are developed to calculate the dynamic pressure of flutter… More >

P. Dabnichki¹, A. Zhivkov²

CMC-Computers, Materials & Continua, Vol.2, No.2, pp. 97-104, 2005, DOI:10.3970/cmc.2005.002.097

Abstract A novel method for geometric reconstruction of smooth pseudo-rotational objects based on elliptic functions is developed. Based on the apparatus of theta functions analytical expressions for the main geometric invariants are derived. Reconstruction of asymmetric and irregular objects is illustrated. The advantages of the proposed technique lay in the following: i) reconstruction is computationally very fast and would allow a qualitative change in the current research practices, i.e. real-time monitoring and analysis of the responses of large cell samples ii) the accuracy of the method is very high and can be flexibly varied iii) the method allows quantitative analysis as… More >

B. Amaziane¹, A. Naji², D. Ouazar³, A. H.-D. Cheng⁴

CMC-Computers, Materials & Continua, Vol.2, No.2, pp. 85-96, 2005, DOI:10.3970/cmc.2005.002.085

Abstract In this paper the optimization of groundwater pumping in coastal aquifers under the threat of saltwater intrusion is investigated. The aquifer is inhomogeneous and contains several hydraulic conductivities zones. The aquifer data such as the hydraulic conductivities are uncertain, but with their expected mean and standard deviation values given. A stochastic boundary element method based on the perturbation technique is employed as the simulation tool. The stochastic optimization is handled by the chance-constrained programming. Genetic algorithm is selected as the optimization tool. Numerical examples of deterministic and stochastic problems are provided to demonstrate the feasibility of the proposed schemes. More >

Chih-Ping Wu¹, Yen-Wei Chi¹

CMC-Computers, Materials & Continua, Vol.1, No.4, pp. 337-352, 2004, DOI:10.3970/cmc.2004.001.337

Abstract Within the framework of the three-dimensional (3D) nonlinear elasticity, a refined asymptotic theory is developed for the nonlinear analysis of laminated circular cylindrical shells. In the present formulation, the basic equations including the nonlinear relations between the finite strains (Green strains) and displacements, the nonlinear equilibrium equations in terms of the Kirchhoff stress components and the generalized Hooke's law for a monoclinic elastic material are considered. After using proper nondimensionalization, asymptotic expansion, successive integration and then bringing the effects of transverse shear deformation into the leading-order level, we obtain recursive sets of the governing equations for various orders. It is… More >

Jiayong Tian^1,2, Ulrich Gabbert², Harald Berger², Xianyue Su¹

CMC-Computers, Materials & Continua, Vol.1, No.4, pp. 327-336, 2004, DOI:10.3970/cmc.2004.001.327

Abstract In this paper, we investigate Lamb wave interaction with delamination in an infinite carbon fiber reinforced plastics (CFRP) laminate by a hybrid method. The infinite CFRP laminate is divided into an exterior zone and an interior zone. In the exterior zone, the wave fields are expressed by wave mode expansion. In the interior zone, the wave fields are modeled by the finite element method (FEM). Considering the continuity condition at the boundary between the exterior and interior zones, the global wave fields can be calculated. Lastly, numerical examples show how a delamination in the laminate influences the mode conversion of… More >

Youssef F. Rashed¹

CMC-Computers, Materials & Continua, Vol.1, No.4, pp. 319-326, 2004, DOI:10.3970/cmc.2004.001.319

Abstract The present paper develops a new technique for treatment of self-weight for building slabs in the boundary element method (BEM). Due to the use of BEM in the analysis, all defined variables are presented on the slab boundary (mesh is defined only along the slab boundary). Self-weight, however, is usually defined over slab domain, hence domain discretisation is required, which spoils the main advantage of the BEM. In this paper a new method is presented to transform self-weight domain integrals to the boundary for such slabs. The proposed method is based on using the so-called Green's first identity. All new… More >

Kunigal N.Shivakumar¹, Shivalingappa Lingaiah², Robert Sadler², Matthew Sharpe²

CMC-Computers, Materials & Continua, Vol.1, No.4, pp. 309-318, 2004, DOI:10.3970/cmc.2004.001.309

Abstract The exfoliation and dispersion of nanoclay (2% by weight) and nanovermiculite (2% by weight) particles in a polymer matrix is analyzed using the Scanning Electron Microscope (SEM) after a low temperature air plasma etch. The plasma etch preferentially removes the polymer to expose the nanoparticles. Both Argon and air have been used as the etching media to study the etching process. SEM analysis illustrate the results of the etching in flat and edge surfaces of both nanoclay (MMT) and nanovermiculite (VMT) filled polymer. Both the MMT and VMT were dispersed using a IKA high shear mixer and a Sonicator. More >

J. Qiu¹, T. Hayase¹, T. Okutani¹

CMC-Computers, Materials & Continua, Vol.1, No.4, pp. 301-308, 2004, DOI:10.3970/cmc.2004.001.301

Abstract In this study, three types of surface motion of wall motion actuators were proposed and used to control the Tollmien-Schlichting (T-S) wave in the laminar boundary layer of a plate. These three types of motion are standing transverse wave (with out-of-plane displacement), traveling transverse wave (with out-of-plane displacement) and standing longitudinal wave (with in-plane displacement). The length of a wall motion actuator was set to 1, 2 or 3 cycles of waveform. Numerical simulation was performed on the generation of T-S wave and its suppression with the three types of surface motion of the wall motion actuator and the dependence… More >