Praveen Ch.¹, Shishir Sinha^1,2

CMC-Computers, Materials & Continua, Vol.9, No.1, pp. 41-50, 2009, DOI:10.3970/cmc.2009.009.041

Abstract Fluid catalytic cracking (FCC) unit plays most important role in the economy of a modern refinery that it is use for value addition to the refinery products. Because of the importance of FCC unit in refining, considerable effort has been done by scientists till now on the modelling of this unit for better understanding and improved productivity. To model a FCC unit we have to know the unknown kinetic parameters of the governing equations.
The basic aim of this paper is to prove that MATLAB^TM can be used as a tool to find unknown kinetic parameters of governing equations for… More >

D.T. Fullwood¹, S.R. Kalidindi², B.L. Adams¹, S. Ahmadi¹

CMC-Computers, Materials & Continua, Vol.9, No.1, pp. 25-40, 2009, DOI:10.3970/cmc.2009.009.025

Abstract Localization relations arise naturally in the formulation of multi-scale models. They facilitate statistical analysis of local phenomena that may contribute to failure related properties. The computational burden of dealing with such relations is high and recent work has focused on spectral methods to provide more efficient models. Issues with the inherent integrations in the framework have led to a tendency towards calibration-based approaches. In this paper a discrete Fourier transform framework is introduced, leading to an extremely efficient basis for the localization relations. Previous issues with the Green's function integrals are resolved, and the method is validated against finite element… More >

Zhenhan Yao¹, Lingfei Gao¹

CMC-Computers, Materials & Continua, Vol.9, No.1, pp. 1-24, 2009, DOI:10.3970/cmc.2009.009.001

Abstract To improve the effectiveness of the lattice model for simulating the failure processes of heterogeneous brittle materials, each lattice element is refined as a subdomain with homogenous material, and is modeled by the boundary element method in this paper. For simplicity, each subdomain is modeled with constant boundary elements. To enhance the efficiency, a row of sub-domains is formed, and then a chain structure of such row-subdomain is constructed. The row-equation systems are solved one by one, and then back substituted, to obtain the final solution. Such a chain subdomain approach of the boundary element method not only reduces the… More >

Chein-ShanLiu¹

CMC-Computers, Materials & Continua, Vol.13, No.3, pp. 219-234, 2009, DOI:10.3970/cmc.2009.013.219

Abstract The present paper reveals a new computational method for the illposed backward wave problem. The Fourier series is used to formulate a first-kind Fredholm integral equation for the unknown initial data of velocity. Then, we consider a direct regularization to obtain a second-kind Fredholm integral equation. The termwise separable property of kernel function allows us to obtain an analytical solution of regularization type. The sufficient condition of the data for the existence and uniqueness of solution is derived. The error estimate of the regularization solution is provided. Some numerical results illustrate the performance of the new method. More >

A.Z. Lorbiecka¹, R.Vertnik², H.Gjerkeš¹, G. Manojlovič², B.Senčič², J. Cesar², B.Šarler^1,3

CMC-Computers, Materials & Continua, Vol.8, No.3, pp. 195-208, 2008, DOI:10.3970/cmc.2008.008.195

Abstract A numerical model is developed for the simulation of solidification grain structure formation (equiaxed to columnar and columnar to equiaxed transitions) during the continuous casting process of steel billets. The cellular automata microstructure model is combined with the macroscopic heat transfer model. The cellular automata method is based on the Nastac's definition of neighborhood, Gaussian nucleation rule, and KGT growth model. The heat transfer model is solved by the meshless technique by using local collocation with radial basis functions. The microscopic model parameters have been adjusted with respect to the experimental data for steel 51CrMoV4. Simulations have been carried out… More >

Ping’en Li^1,2, Xianyue Su^1,3

CMC-Computers, Materials & Continua, Vol.8, No.3, pp. 173-194, 2008, DOI:10.3970/cmc.2008.008.173

Abstract Applying the Stroh theory and based on the works of Hwu and Ting (1989), the complex function solution of stress and displacement fields around an open borehole in intrinsic anisotropic formation under horizontal terrestrial stress field is obtained. For cross-dipole flexural wave propagation along borehole axis, using the perturbation method, the acoustoelastic equation describing the relation between the alteration in phase velocity and terrestrial stress as well as formation intrinsic anisotropy is derived. At last, the numerical examples are provided for both the cases of fast and slow formation where the symmetry axis of a transversely isotropic (TI) formation makes… More >

M. Daian¹, A. Taube², G. Torgovnikov³, G. Daian⁴, Y. Shramkov⁵

CMC-Computers, Materials & Continua, Vol.8, No.3, pp. 165-172, 2008, DOI:10.3970/cmc.2008.008.165

Abstract Microwave wood modification and treatment technologies become more and more essential within the wood industry due to their technical and economical advantages. Microwave processing of wood involves many complicated physical phenomena and requires a very careful control of variables (such as intensity of microwave power, loading period, maximum temperature, etc.) in order to reduce structural deformations of the processed wood. To optimise and minimise the project design engineers' work, modelling and simulation of the microwave energy-wood interaction represents an indispensable tool.
This research work has been undertaken with the aim to design and optimise microwave applicators for microwave pre-drying… More >

R. Issa¹, D. Violeau¹

CMC-Computers, Materials & Continua, Vol.8, No.3, pp. 151-164, 2008, DOI:10.3970/cmc.2008.008.151

Abstract Breaking waves can run up at the shoreline, inundating coastal regions and causing large property damage and loss of life. In order to proceed to the design of sea defence structures and estimate the possible damage resulting from sea submersion due to a tsunami for instance, it is thus crucial to understand these phenomena. However, due to the mathematical difficulties caused by the complexities of the fluid motion associated with breaking wave, a fully theoretical approach is not possible. Thus most of the investigations regarding breaking waves are experimental and numerical. Some methods were recently developed to perform such simulations,… More >

Asif Husain¹, M. Guniganti², D. K. Sehgal², R. K. Pandey²

CMC-Computers, Materials & Continua, Vol.8, No.3, pp. 133-150, 2008, DOI:10.3970/cmc.2008.008.133

Abstract This paper describes an approach to identify the mechanical properties i.e. fracture and yield strength of steels. The study involves the FE simulation of shear punch test for various miniature specimens thickness ranging from 0.20mm to 0.80mm for four different steels using ABAQUS code. The experimental method of the miniature shear punch test is used to determine the material response under quasi-static loading. The load vs. displacement curves obtained from the FE simulation miniature disk specimens are compared with the experimental data obtained and found in good agreement. The resulting data from the load vs. displacement diagrams of different steels… More >

Chih-Ping Wu^1,2, Kuan-Hao Chiu², Yung-Ming Wang²

CMC-Computers, Materials & Continua, Vol.8, No.2, pp. 93-132, 2008, DOI:10.3970/cmc.2008.008.093

Abstract The article is to present an overview of various three-dimensional (3D) analytical approaches for the analysis of multilayered and functionally graded (FG) piezoelectric plates and shells. The reported 3D approaches in the literature are classified as four different approaches, namely, Pagano's classical approach, the state space approach, the series expansion approach and the asymptotic approach. Both the mixed formulation and displacement-based formulation for the 3D analysis of multilayered piezoelectric plates are derived. The analytical process, based on the 3D formulations, for the aforementioned approaches is briefly interpreted. The present formulations of multilayered piezoelectric plates can also be used for the… More >