Saydul Akbar Murad¹, Apurba Adhikary², Abu Jafar Md Muzahid¹, Md. Murad Hossain Sarker³, Md. Ashikur Rahman Khan², Md. Bipul Hossain², Anupam Kumar Bairagi^4,*, Mehedi Masud⁵, Md. Kowsher⁶

Intelligent Automation & Soft Computing, Vol.34, No.1, pp. 87-103, 2022, DOI:10.32604/iasc.2022.024777

Abstract Asthma is a disease which attacks the lungs and that affects people of all ages. Asthma prediction is crucial since many individuals already have asthma and increasing asthma patients is continuous. Machine learning (ML) has been demonstrated to help individuals make judgments and predictions based on vast amounts of data. Because Android applications are widely available, it will be highly beneficial to individuals if they can receive therapy through a simple app. In this study, the machine learning approach is utilized to determine whether or not a person is affected by asthma. Besides, an android application is being created to… More >

Mertcan Cihan, BlaŽ Hudobivnik, Fadi Aldakheel, Peter Wriggers^*

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.3, pp. 1151-1180, 2021, DOI:10.32604/cmes.2021.016851

Abstract The virtual element method (VEM) can be seen as an extension of the classical finite element method (FEM) based on Galerkin projection. It allows meshes with highly irregular shaped elements, including concave shapes. So far the virtual element method has been applied to various engineering problems such as elasto-plasticity, multiphysics, damage and fracture mechanics. This work focuses on the extension of the virtual element method to efficient modeling of nonlinear elasto-dynamics undergoing large deformations. Within this framework, we employ low-order ansatz functions in two and three dimensions for elements that can have arbitrary polygonal shape. The formulations considered in this… More >

Saad Nader^1,2, Felipe Guzman³, Raphael Becar¹, César Segovia⁴, Cecilia Fuentealba³, Miguel Peirera³, Evelyne Mauret², Nicolas Brosse^1,*

Journal of Renewable Materials, Vol.10, No.2, pp. 263-271, 2022, DOI:10.32604/jrm.2022.017923

Abstract The reinforcing impact of Lignocellulosic micro and nanofibrillated cellulose (L-MNFCs) obtained from Eucalyptus Globulus bark in Urea-Formaldehyde UF adhesive was tested. L-MNFCs were prepared by an environmentally friendly, low-cost process using a combination process involving steam explosion followed by refining and ultra-fine grinding. Obtained L-MNFCs showed a web-like morphology with some aggregates and lignin nanodroplets. They present a mixture of residual fibers and fine elements with a width varying between 5 nm to 20 μm, respectively. The effects of the addition of low amounts of L-MNFCs (1% wt.) on the properties of three different adhesives (Urea-Formaldehyde UF, Phenol-Formaldehyde PF, and Tannin-Hexamine TH)… More > Graphic Abstract

Ney Augusto Dumont

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 2-2, 2021, DOI:10.32604/icces.2021.08187

Abstract The mathematical modeling of microdevices, in which structure and microstructure have approximately the same scale of magnitude, as well as of macrostructures of markedly granular or crystal nature (microcomposites), demands a nonlocal approach for strains and stresses. The present proposition is based on a simplified strain gradient theory laid down by Aifantis, which has also been applied mainly by Beskos and collaborators in the context of the boundary element method. This paper is an extension of a presentation made during the ICCES 2014 Conference in Crete, Greece, now relying on machine-precision evaluation of all singular and hypersingular integrals required in… More >

Weidong Lei¹, Hai Zhou^1,*, Hongjun Li², Rui Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.2, pp. 577-597, 2021, DOI:10.32604/cmes.2021.011857

Abstract In order to simulate the propagation process of subway vibration of parallel tunnels in semi-infinite rocks or soils, time domain boundary element method (TD-BEM) formulation for analyzing the dynamic response of twin-parallel circular tunnels in an elastic semi-infinite medium is developed in this paper. The time domain boundary integral equations of displacement and stress for the elastodynamic problem are presented based on Betti’s reciprocal work theorem, ignoring contributions from initial conditions and body forces. In the process of establishing time domain boundary integral equations, some virtual boundaries are constructed between finite boundaries and the free boundary to form a boundary… More >

Zhenghao Yang, Erkan Oterkus^*, Selda Oterkus

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.2, pp. 527-544, 2020, DOI:10.32604/cmes.2020.010804

Abstract In this study, a new state-based peridynamic formulation is developed for functionally graded Euler-Bernoulli beams. The equation of motion is developed by using Lagrange’s equation and Taylor series. Both axial and transverse displacements are taken into account as degrees of freedom. Four different boundary conditions are considered including pinned support-roller support, pinned support-pinned support, clamped-clamped and clamped-free. Peridynamic results are compared against finite element analysis results for transverse and axial deformations and a very good agreement is observed for all different types of boundary conditions. More >

Cheinshan Liu^{1, 2}, Chunglun Kuo¹, Jiangren Chang^{3, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.1, pp. 33-48, 2020, DOI:10.32604/cmes.2020.08490

Abstract In the optimal control problem of nonlinear dynamical system, the Hamiltonian formulation is useful and powerful to solve an optimal control force. However, the resulting Euler-Lagrange equations are not easy to solve, when the performance index is complicated, because one may encounter a two-point boundary value problem of nonlinear differential algebraic equations. To be a numerical method, it is hard to exactly preserve all the specified conditions, which might deteriorate the accuracy of numerical solution. With this in mind, we develop a novel algorithm to find the solution of the optimal control problem of nonlinear Duffing oscillator, which can exactly… More >

Jidong Zhang^1,2,*, Wentao Sui², Jaspreet Dhupia³

Sound & Vibration, Vol.53, No.2, pp. 38-49, 2019, DOI:10.32604/sv.2019.04362

Abstract Occurrence of gear rattle in transmission systems can result in severe vibration and noise, which in applications such as automobiles is an important source of user discomfort. As a result , the reduction of the rattling noise has attracted lot of concerns. The rattling noise level is affected by several gearbox parameters, an understanding of which is essential to prevent the expensive design modifications at later stages of product development. To develop such understanding at the gearbox design stage, this paper analytically evaluates the gear parameters’ effect on the root mean square of the wheel gear acceleration under idling condition,… More >

H.S. Wijesinghe¹, N.G. Hadjiconstantinou²

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.6, pp. 515-526, 2004, DOI:10.3970/cmes.2004.005.515

Abstract We present an implicit hybrid atomisticcontinuum formulation for unsteady, viscous, incompressible flows. The coupling procedure is derived from a domain decomposition method known as the Schwarz alternating method. A dilute gas impulsive Couette flow test problem is used to verify the hybridscheme. Finally, a method to reduce computational costs through limited ensemble averaging is presented. The implicit formulation proposed here is expected to be significantly faster than a time explicit approach based on a compressible formulation for the simulation of low speed flows such as those found in micro- and nano–scale devices. More >

G. C. Bourantas¹, E. D. Skouras^2,3, V. C. Loukopoulos⁴, G. C. Nikiforidis¹

CMES-Computer Modeling in Engineering & Sciences, Vol.64, No.2, pp. 187-212, 2010, DOI:10.3970/cmes.2010.064.187

Abstract Meshfree point collocation method (MPCM) is developed, solving the velocity-vorticity formulation of Navier-Stokes equations, for two-dimensional, steady state incompressible viscous flow problems in the presence of heat transfer. Particular emphasis is placed on the application of the velocity-correction method, ensuring the continuity equation. The Gaussian Radial Basis Functions (GRBF) interpolation is employed to construct the shape functions in conjunction with the framework of the point collocation method. The cases of forced, natural and mixed convection in a 2D rectangular enclosure are examined. The accuracy and the stability of the proposed scheme are demonstrated through three representative, well known and established… More >