A. M. Abd-Alla^1,*, Hanaa Abu-Zinadah², S. M. Abo-Dahab³, J. Bouslimi^4,5, M. Omri⁶

CMC-Computers, Materials & Continua, Vol.68, No.2, pp. 1485-1504, 2021, DOI:10.32604/cmc.2021.012586 - 13 April 2021

Abstract This article is aimed at describing the way rotation and magnetic field affect the propagation of waves in an infinite poroelastic cylindrical bone. It offers a solution with an exact closed form. The authors got and examined numerically the general frequency equation for poroelastic bone. Moreover, they calculated the frequencies of poroelastic bone for different values of the magnetic field and rotation. Unlike the results of previous studies, the authors noticed little frequency dispersion in the wet bone. The proposed model will be applicable to wide-range parametric projects of bone mechanical response. Examining the vibration More >

Jaafar Hallal^1,2,3,*, Mohammad Hammoud^2,3, Mahmoud Fakih^2,3,4, Ali Hallal^2,3

Sound & Vibration, Vol.54, No.4, pp. 225-236, 2020, DOI:10.32604/sv.2020.011513 - 25 November 2020

Abstract The vibrations behavior analysis is an essential step in the mechanical design process. Several methods such as analytical modelling, numerical analysis and experimental measurements can be used for this purpose. However, the numerical or analytical models should be validated through experimental measurements, usually expensive. This paper introduces an inexpensive smartphone as an accurate, non-intrusive vibrations’ behavior measurement device. An experimental measurement procedure based on the video processing method is presented. This procedure allows the measurement of the natural frequencies and the mode shapes of a vibrating structure, simply by using a smartphone built-in camera. The… More >

Jianping Sun¹, Jan Niederwestberg^2,*, Fangchao Cheng¹, Yinghei Chui²

Journal of Renewable Materials, Vol.8, No.3, pp. 319-328, 2020, DOI:10.32604/jrm.2020.08696 - 01 March 2020

Abstract Cross laminated timber (CLT) panels, which are used as load bearing plates and shear panels in timber structures, can serve as roofs, walls and floors. Since timber is construction material with relatively less stiffness, the design of such structures is often driven by serviceability criteria, such as deflection and vibration. Therefore, accurate vibration and elastic properties are vital for engineered CLT products. The objective of this research is to explore a method to determine the natural frequencies of orthotropic wood plates efficiently and fast. The method was developed based on vibration signal processing by wavelet More >

Amirabbas Haidarpour, Kong Fah Tee^*

Structural Durability & Health Monitoring, Vol.14, No.1, pp. 1-17, 2020, DOI:10.32604/sdhm.2020.08792 - 01 March 2020

Abstract This paper provides a model updating approach to detect, locate, and characterize damage in structural and mechanical systems by examining changes in measured vibration responses. Research in vibration-based damage identification has been rapidly expanding over the last few decades. The basic idea behind this technology is that modal parameters (notably frequencies, mode shapes, and modal damping) are functions of the physical properties of the structure (mass, damping, and stiffness). Therefore, changes in the physical properties will cause changes in the modal properties which could be obtained by structural health monitoring (SHM). Updating is a process… More >

Surkay D. Akbarov^1,2, Hatam H. Guliyev³, Yusif M. Sevdimaliyev⁴, Nazmiye Yahnioglu^5,*

CMC-Computers, Materials & Continua, Vol.55, No.2, pp. 359-380, 2018, DOI:10.3970/cmc.2018.00173

Abstract The paper deals with a development of the discrete-analytical method for the solution of the dynamical problems of a hollow sphere with inhomogeneous initial stresses. The examinations are made with respect to the problem on the natural vibration of the hollow sphere the initial stresses in which is caused by internal and external uniformly distributed pressure. The initial stresses in the sphere are determined within the scope of the exact equations of elastostatics. It is assumed that after appearing this static initial stresses the sphere gets a dynamical excitation and mechanical behavior of the sphere… More >

A.M. Farhan^{1, 2}

CMC-Computers, Materials & Continua, Vol.53, No.2, pp. 129-156, 2017, DOI:10.3970/cmc.2017.053.133

Abstract Employing Biot’s theory of wave propagation in liquid saturated porous media, the effect of rotation and magnetic field on wave propagation in a hollow poroelastic circular of infinite extent are investigated. An exact closed form solution is presented. General frequency equations for propagation of poroelastic cylinder are obtained when the boundaries are stress free. The frequencies are calculated for poroelastic cylinder for different values of magnetic field and rotation. Numerical results are given and illustrated graphically. The results indicate that the effect of rotation, and magnetic field are very pronounced. Such a model would be More >

Foad Nazari¹, Mohammad Hossein Abolbashari^1,2, Seyed Mahmoud Hosseini³

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.4, pp. 271-299, 2015, DOI:10.3970/cmes.2015.105.271

Abstract Present study is concerned with three dimensional natural frequency analysis of functionally graded sandwich rectangular plates using Meshless Local Petrov-Galerkin (MLPG) method and Artificial Neural Networks (ANNs).The plate consists of two homogeneous face sheets and a power-law FGM core. Natural frequencies of the plate are obtained by 3D MLPG method and are verified with available references. Convergence study of the first four natural frequencies for different node numbers is the next step. Also, effects of two parameters of “FG core to plate thickness ratio” and “volume fraction index” on natural frequencies of plate are investigated. More >

Seyed Mahmoud Hosseini ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.1, pp. 1-29, 2013, DOI:10.3970/cmes.2013.095.001

Abstract In this article, the effects of carbon nanotubes distributions on natural frequency are studied for a functionally graded nanocomposite thick hollow cylinder reinforced by single-walled carbon nanotubes using a hybrid mesh-free method. The FG nanocomposite cylinder is excited by a shock loading, which is applied on the inner surface of cylinder. The first natural frequency is obtained for various nonlinear grading patterns of distributions of the aligned carbon nanotubes. The effects of various nonlinear grading patterns on natural frequency are obtained and discussed in details. The presented hybrid mesh-free method is based on the generalized More >

Zichun Yang^1,2,3, Wencai Sun²

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.2, pp. 193-212, 2013, DOI:10.3970/cmes.2013.092.193

Abstract The set-based structural eigenvalue problem is defined, by expressing the uncertainties of the structural parameters in terms of various convex sets. A new method based on Kriging model and Particle Swarm Optimization (PSO) is proposed for solving this problem. The introduction of the Kriging model into this approach can effectively reduce the computational burden especially for largescale structures. The solutions of the non-linear and non-monotonic problems are more accurate than those obtained by other methods in the literature with the PSO algorithm. The experimental points for Kriging model are sampled according to Latin hypercube sampling More >

Wanil Byun¹, Seung Jo Kim²

CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.6, pp. 551-576, 2012, DOI:10.3970/cmes.2012.086.551

Abstract A structural eigensolver for large-scale finite element analysis is developed. The algorithms and data structures implemented in this paper are well suited for a distributed memory environment. As an eigenvalue extracting algorithm, the well-known M orthogonal block Lanczos iteration incorporated with a parallel multifrontal solver (PMFS) was chosen. Basically, for the better performance of this algorithm in parallel computation, Lanczos vector allocation, mass matrix multiplication, and M inner product procedures were efficiently implemented. And the PMFS for a linear equation which is the most time-consuming part during Lanczos iterations was improved. The idea was to More >