D.L. Young^1,2, C.C. Tsai³, Y.C. Lin¹, C.S. Chen⁴

CMC-Computers, Materials & Continua, Vol.4, No.1, pp. 1-10, 2006, DOI:10.3970/cmc.2006.004.001

Abstract This paper describes the method of fundamental solutions (MFS) to solve eigenfrequencies of plate vibrations by utilizing the direct determinant search method. The complex-valued kernels are used in the MFS in order to avoid the spurious eigenvalues. The benchmark problems of a circular plate with clamped, simply supported and free boundary conditions are studied analytically as well as numerically using the discrete and continuous versions of the MFS schemes to demonstrate the major results of the present paper. Namely only true eigenvalues are contained and no spurious eigenvalues are included in the range of direct determinant search method. Consequently analytical… More >

Thanh Q. Nguyen^1,2, Thao T. D. Nguyen³, H. Nguyen-Xuan^4,5,*, Nhi K. Ngo^1,2

CMC-Computers, Materials & Continua, Vol.61, No.1, pp. 27-53, 2019, DOI:10.32604/cmc.2019.07756

Abstract This paper presents a new approach using correlation and cross-correlation coefficients to evaluate the stiffness degradation of beams under moving load. The theoretical study of identifying defects by vibration methods showed that the traditional methods derived from the vibration measurement data have not met the needs of the actual issues. We show that the correlation coefficients allow us to evaluate the degree and the effectiveness of the defects on beams. At the same time, the cross-correlation model is the basis for determining the relative position of defects. The results of this study are experimentally conducted to confirm the relationship between… More >

Yang Yu¹, Zeyu Xiong^1,*, Yueshan Xiong¹, Weizi Li²

CMC-Computers, Materials & Continua, Vol.61, No.1, pp. 103-118, 2019, DOI:10.32604/cmc.2019.05154

Abstract Logistic regression is often used to solve linear binary classification problems such as machine vision, speech recognition, and handwriting recognition. However, it usually fails to solve certain nonlinear multi-classification problem, such as problem with non-equilibrium samples. Many scholars have proposed some methods, such as neural network, least square support vector machine, AdaBoost meta-algorithm, etc. These methods essentially belong to machine learning categories. In this work, based on the probability theory and statistical principle, we propose an improved logistic regression algorithm based on kernel density estimation for solving nonlinear multi-classification. We have compared our approach with other methods using non-equilibrium samples,… More >

Surkay D. Akbarov^{1, 2, *}, Mahir A. Mehdiyev³

CMC-Computers, Materials & Continua, Vol.54, No.1, pp. 61-81, 2018, DOI:10.3970/cmc.2018.054.061

Abstract The paper develops and employs analytical-numerical solution method for the study of the time-harmonic dynamic stress field in the system consisting of the hollow cylinder and surrounding elastic medium under the non-axisymmetric forced vibration of this system. It is assumed that in the interior of the hollow cylinder the point-located with respect to the cylinder axis, non-axisymmetric with respect to the circumferential direction and uniformly distributed time-harmonic forces act. Corresponding boundary value problem is solved by employing of the exponential Fourier transformation with respect to the axial coordinate and by employing of the Fourier series expansion of these transformations. Numerical… More >

A. M. Abd-Alla^{1, 2}, S. M. Abo-Dahab^{1, 3}, Aftab Khan⁴

CMC-Computers, Materials & Continua, Vol.53, No.1, pp. 49-72, 2017, DOI:10.3970/cmc.2017.053.052

Abstract In this paper, we investigated the propagation of the rmo elastic surface waves in fibre-reinforced anisotropic general viscoelastic media of higher order ofnth order, including time rate of strain under the influence of rotation.The general surface wave speed is derived to study the effects of rotation and thermal on surface waves. Particular cases for Stoneley, Love and Rayleigh waves are discussed. The results obtained in this investigation are more general in the sense that some earlier published results are obtained from our result as special cases. Our results for viscoelastic of order zero are well agreed to fibre-reinforced materials. Comparison… More >

U. Babuscu Yesil¹

CMC-Computers, Materials & Continua, Vol.53, No.1, pp. 1-22, 2017, DOI:10.3970/cmc.2017.053.001

Abstract Forced and natural vibrations of a rectangular pre-stressed orthotropic composite plate containing two neighboring cylindrical cavities whose cross sections are rectangular with rounded-off corners are investigated numerically. It is assumed that all the end surfaces of the rectangular pre-stressed composite plate are simply supported and subjected to a uniformly distributed normal time-harmonic force on the upper face plane. The considered problem is formulated within the Three-Dimensional Linearized Theory of Elastic Waves in Initially Stressed Bodies (TDLTEWISB). The influence of mechanical and geometrical parameters as well as the initial stresses and the effect of cylindrical cavities on the dynamical characteristics of… More >

Xing Wei^1,2, Wen Chen², Bin Chen^2,3, Bin Chen^1,4, Bin Chen², Bin Chen¹

CMC-Computers, Materials & Continua, Vol.52, No.1, pp. 53-71, 2016, DOI:10.3970/cmc.2016.052.053

Abstract A new wavelet finite element method (WFEM) is constructed in this paper and two elements for bending and free vibration problems of a stiffened plate are analyzed. By means of generalized potential energy function and virtual work principle, the formulations of the bending and free vibration problems of the stiffened plate are derived separately. Then, the scaling functions of the B-spline wavelet on the interval (BSWI) are introduced to discrete the solving field variables instead of conventional polynomial interpolation. Finally, the corresponding two problems can be resolved following the traditional finite element frame. There are some advantages of the constructed… More >

Sen-Yung Lee¹, Shueei-Muh Lin^2,3, Kai-Ping Chang¹

CMC-Computers, Materials & Continua, Vol.51, No.1, pp. 1-19, 2016, DOI:10.3970/cmc.2016.051.001

Abstract The two coupled governing differential equations for the out-of-plane vibrations of non-uniform beams with variable curvature are derived via the Hamilton's principle. These equations are expressed in terms of flexural and torsional displacements simultaneously. In this study, the analytical method is proposed. Firstly, two physical parameters are introduced to simplify the analysis. One derives the explicit relations between the flexural and the torsional displacements which can also be used to reduce the difficulty in experimental measurements. Based on the relation, the two governing characteristic differential equations with variable coefficients can be uncoupled into a sixth-order ordinary differential equation in terms… More >

M. P. Muthuraj^1,2, K. Nithyapriya¹

CMC-Computers, Materials & Continua, Vol.48, No.2, pp. 119-132, 2015, DOI:10.3970/cmc.2015.048.119

Abstract The maintenance, upgrading and replacement of existing bridges have become urgent requirement and a challenging task for the construction sector. Bridge decks made of fibre reinforced polymers (FRP), have been widely adopted both in new construction and replacement of existing bridge decks. This paper reports the studies carried out hand lay-up multicellular glass fibre reinforced polymer. Multicellular bridge deck panels with various cross sectional profiles have been analysed using a general purpose finite element software ANSYS. A cross sectional profile that satisfied the deflection criteria with minimum weight was selected for analysis and fabrication. Six multicellular GFRP composite bridge deck… More >

Yanbin Wang^1,2, Deli Gao¹, Jun Fang¹

CMC-Computers, Materials & Continua, Vol.48, No.1, pp. 57-75, 2015, DOI:10.3970/cmc.2015.048.057

Abstract In this paper, the mechanical model to analyze the riser lateral vibration displacement and stress distribution in installation has been established via variational approach and the principle of minimum potential energy. In this model, the influence of vessel motion on riser lateral vibration has been taken into consideration. The specific expression of lateral vibration has also been figured out according to the boundary conditions and initial conditions. At last, the variations of riser maximum lateral displacement and stress distribution on water depth (WD), wave height, wave period, riser OD, BOPS weight have been discussed. More >