Ola Ragb¹, Mokhtar Mohamed², Mohamed S. Matbuly¹, Omer Civalek^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.3, pp. 2193-2217, 2023, DOI:10.32604/cmes.2023.028992

Abstract Four numerical schemes are introduced for the analysis of photocurrent transients in organic photovoltaic devices. The mathematical model for organic polymer solar cells contains a nonlinear diffusion–reaction partial differential equation system with electrostatic convection attached to a kinetic ordinary differential equation. To solve the problem, Polynomial-based differential quadrature, Sinc, and Discrete singular convolution are combined with block marching techniques. These schemes are employed to reduce the problem to a nonlinear algebraic system. The iterative quadrature technique is used to solve the reduced problem. The obtained results agreed with the previous exact one and the finite element method. Further, the effects… More > Graphic Abstract

Amthal Hakim¹, Wael Slika^1,*, Rawan Machmouchi¹, Adel Elkordi²

Structural Durability & Health Monitoring, Vol.17, No.3, pp. 175-194, 2023, DOI:10.32604/sdhm.2022.023027

Abstract Corrosion of reinforcing steel in concrete elements causes minor to major damage in different aspects. It may lead to spalling of concrete cover, reduction of section’s capacity and can alter the dynamic properties. For the dynamic properties, natural frequency is to be a reliable indicator of structural integrity that can be utilized in non-destructive corrosion assessment. Although the correlation between natural frequency and corrosion damage has been reflected in different experimental programs, few attempts have been made to investigate this relationship in forward modeling and/or structural health monitoring techniques. This can be attributed to the limited available data, the complex… More >

Muhammad Zafar^1,#,*, Muhammad Saif Ullah^1,#, Tareq Manzoor², Muddassir Ali³, Kashif Nazar⁴, Shaukat Iqbal⁵, Habib Ullah Manzoor⁶, Rizwan Haider¹, Woo Young Kim^7,*

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.2, pp. 723-749, 2022, DOI:10.32604/cmes.2022.017257

Abstract In recent years, the emergence of nanotechnology experienced incredible development in the field of medical sciences. During the past decade, investigating the characteristics of nanoparticles during fluid flow has been one of the intriguing issues. Nanoparticle distribution and uniformity have emerged as substantial criteria in both medical and engineering applications. Adverse effects of chemotherapy on healthy tissues are known to be a significant concern during cancer therapy. A novel treatment method of magnetic drug targeting (MDT) has emerged as a promising topical cancer treatment along with some attractive advantages of improving efficacy, fewer side effects, and reduce drug dose. During… More >

Ali Maghami¹, Farzad Shahabian¹, Seyed Mahmoud Hosseini^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.3, pp. 877-907, 2019, DOI:10.32604/cmes.2019.08019

Abstract The suitability of six higher order root solvers is examined for solving the nonlinear equilibrium equations in large deformation analysis of structures. The applied methods have a better convergence rate than the quadratic Newton-Raphson method. These six methods do not require higher order derivatives to achieve a higher convergence rate. Six algorithms are developed to use the higher order methods in place of the NewtonRaphson method to solve the nonlinear equilibrium equations in geometrically nonlinear analysis of structures. The higher order methods are applied to both continuum and discrete problems (spherical shell and dome truss). The computational cost and the… More >

K.Y.Sze, Y.X.Zhou

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.3, pp. 91-92, 2011, DOI:10.3970/icces.2011.017.091

Abstract In this paper, new rotation-free beam and shell models are presented. Unlike the finite element models, rotation-free models employ integration domains which are smaller than the domains of influence. Hence, they are sometimes known as overlapping elements. The present linear straight beam and plate models are the same as those of Phaal & Calladine in the sense that quadratic interpolation are employed to construct the transverse deflection. Nevertheless, Phaal & Calladine turned to a hinged-angle approach for the linear curved beam and shell models and did not present the geometric nonlinear models. In our formulation, the linear curved beam and… More >

Paulo M. Pimenta

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.3, pp. 85-86, 2011, DOI:10.3970/icces.2011.017.085

Abstract This work addresses the development of some alternative hybrid and mixed variational formulations for the geometrically-exact three-dimensional first-order-shear shell boundary value problem [1,2]. In the framework of the complementary-energy-based formulations, a Legendre transformation is used to introduce the complementary energy density in the variational statements as a function of the cross-sectional resultants only. The corresponding variational principles are shown to feature stationarity within the framework of the boundary-value-problem. The main features of the principles are highlighted, giving special attention to their relationships from both theoretical and numerical point of view.

Variational principles constitute the core of the development of… More >

B. Brank¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.3, pp. 81-86, 2007, DOI:10.3970/icces.2007.002.081

Abstract First we shortly present several low-order (4-node) shell finite element formulations (based on Reissner-Mindlin kinematics) that allow for accurate and efficient (with coarse and distorted meshes) analysis of shell-like structures subjected to large deformations and rotations. The formulations are based on mixed variational principle, enhanced assumed strain (EAS) method (based on Green-Lagrange strains) and assumed natural strain (ANS) method. The EAS method is used in all formulations in order to improve both membrane and bending behavior of the 4-node element (the formulations differ from one another by the number of assumed EAS parameters), and the ANS method is used to… 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 >

Smitha Gopinath^1,2, A. Ramachandra Murthy¹, Bhaskar Srivastava¹, V. Ramesh kumar¹, Nagesh R. Iyer¹

CMC-Computers, Materials & Continua, Vol.27, No.1, pp. 73-100, 2012, DOI:10.3970/cmc.2012.027.073

Abstract The present study investigates the behavior of concrete specimens confined with woven roving glass fabrics under uniaxial compression. The fabric made up of 360G.S.M. woven roved E-glass is embedded in a polyester resin before application. Experimental investigations have been carried out on confined and unconfined concrete specimens of size 150 mm (diameter) X 300 mm (height) under a displacement controlled loading. The effect of number of layers on confinement has also been investigated. Load versus deflection plots have been obtained for all the specimens. Numerical studies have been performed on the confinement effect of the wrapped concrete specimens. A non-linear… More >

Xinzheng Lu^1,*, Yuan Tian², Chujin Sun², Shuhao Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.3, pp. 561-582, 2019, DOI:10.32604/cmes.2019.04770

Abstract The open-source finite element software, OpenSees, is widely used in the earthquake engineering community. However, the shell elements and explicit algorithm in OpenSees still require further improvements. Therefore, in this work, a triangular shell element, NLDKGT, and an explicit algorithm are proposed and implemented in OpenSees. Specifically, based on the generalized conforming theory and the updated Lagrangian formulation, the proposed NLDKGT element is suitable for problems with complicated boundary conditions and strong nonlinearity. The accuracy and reliability of the NLDKGT element are validated through typical cases. Furthermore, by adopting the leapfrog integration method, an explicit algorithm in OpenSees and a… More >