Rafael Marin Ferro^1,2,*, Renato Pavanello²

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.2, pp. 1371-1397, 2023, DOI:10.32604/cmes.2023.026043

Abstract This work analyzes the implementation of a continuous method of structural topology optimization (STO) using open-source software for all stages of the topology optimization problem: modeling, sensitivity analysis and optimization. Its implementation involves three main components: numerical analysis using the Finite Element Method (FEM), sensitivity analysis using an Adjoint method and an optimization solver. In order to allow the automated numerical solution of Partial Differential Equations (PDEs) and perform a sensitivity analysis, FEniCS and Dolfin Adjoint software are used as tools, which are open-source code. For the optimization process, Ipopt (Interior Point OPTimizer) is used, which is a software package… More >

Woochan Lee¹, Woobin Park¹, Jaeyoung Park², Young-Joon Kim³, Moonseong Kim^4,*

Intelligent Automation & Soft Computing, Vol.36, No.2, pp. 1585-1602, 2023, DOI:10.32604/iasc.2023.033112

Abstract The finite element method is a key player in computational electromagnetics for designing RF (Radio Frequency) components such as waveguides. The frequency-domain analysis is fundamental to identify the characteristics of the components. For the conventional frequency-domain electromagnetic analysis using FEM (Finite Element Method), the system matrix is complex-numbered as well as indefinite. The iterative solvers can be faster than the direct solver when the solver convergence is guaranteed and done in a few steps. However, such complex-numbered and indefinite systems are hard to exploit the merit of the iterative solver. It is also hard to benefit from matrix factorization techniques… More >

Yinlong Wang¹, Zhao Li², Ziran Li^1,*, Yang Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 1187-1208, 2023, DOI:10.32604/cmes.2022.022596

Abstract The comprehensive tire building and shaping processes are investigated through the finite element method (FEM) in this article. The mechanical properties of the uncured rubber from different tire components are investigated through cyclic loading-unloading experiments under different strain rates. Based on the experiments, an elasto-viscoplastic constitutive model is adopted to describe the mechanical behaviors of the uncured rubber. The distinct mechanical properties, including the stress level, hysteresis and residual strain, of the uncured rubber can all be well characterized. The whole tire building process (including component winding, rubber bladder inflation, component stitching and carcass band folding-back) and the shaping process… More >

Enran Hou¹, Umar Nazir², Samaira Naz³, Muhammad Sohail^2,4,*, Muhammad Nadeem⁵, Jung Rye Lee⁶, Choonkil Park^7,*, Ahmed M. Galal^8,9

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 1393-1411, 2023, DOI:10.32604/cmes.2022.022500

Abstract In this article, the rheology of Ferro-fluid over an axisymmetric heated disc with a variable magnetic field by considering the dispersion of hybrid nanoparticles is considered. The flow is assumed to be produced by the stretching of a rotating heated disc. The contribution of variable thermophysical properties is taken to explore the momentum, mass and thermal transportation. The concept of boundary layer mechanism is engaged to reduce the complex problem into a simpler one in the form of coupled partial differential equations system. The complex coupled PDEs are converted into highly nonlinear coupled ordinary differential equations system (ODEs) and the… More >

Ankush Kapoor¹, Pradeep Kumar^2,*, Ranjan Mishra³

CMC-Computers, Materials & Continua, Vol.74, No.1, pp. 341-361, 2023, DOI:10.32604/cmc.2023.028874

Abstract Frequency selective surfaces (FSSs) play an important role in wireless systems as these can be used as filters, in isolating the unwanted radiation, in microstrip patch antennas for improving the performance of these antennas and in other 5G applications. The analysis and design of the double concentric ring frequency selective surface (DCRFSS) is presented in this research. In the sub-6 GHz 5G FR1 spectrum, a computational synthesis technique for creating DCRFSS based spatial filters is proposed. The analytical tools presented in this study can be used to gain a better understanding of filtering processes and for constructing the spatial filters.… More >

Linchuan Liu¹, Jian Wu², Zhongwei Hu², Xiaochao Jin^1,*, Pin Lu¹, Tao Zhang², Xueling Fan^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.2, pp. 1219-1236, 2023, DOI:10.32604/cmes.2022.022221

Abstract A virtual wall thickness method is developed to simulate the temperature field of turbine blades with thermal barrier coatings (TBCs), to simplify the modeling process and improve the calculation efficiency. The results show that the virtual wall thickness method can improve the mesh quality by 20%, reduce the number of meshes by 76.7% and save the calculation time by 35.5%, compared with the traditional real wall thickness method. The average calculation error of the two methods is between 0.21% and 0.93%. Furthermore, the temperature at the blade leading edge is the highest and the average temperature of the blade pressure… More >

Lingyun Zhao^1,2, Heng Yang^3,4,*, Yuanlong Wei^1,2,*, Yuhuan Bu^3,4, Shaorui Jing^3,4, Peiming Zhou^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 329-344, 2023, DOI:10.32604/fdmp.2022.020216

Abstract Perforation and fracturing are typically associated with the development of coalbed methane wells. As the cement sheath is prone to failure during this process, in this work, the effects of the casing pressure, elastic modulus of the cement, elastic modulus of the formation, and casing eccentricity on the resulting stresses are analyzed in the frame of a finite element method. Subsequently, sensitivity response curves of the cement sheath stress are plotted by normalizing all factors. The results show that the maximum circumferential stress and Mises stress of the cement sheath increase with the casing internal pressure, elastic modulus of the… More > Graphic Abstract

S. Pradeepkumar^*, P. Nagaraj

Sound & Vibration, Vol.56, No.3, pp. 221-233, 2022, DOI:10.32604/sv.2022.014889

Abstract Vibrational characteristics in small horizontal axis wind turbine system are presented in this study with a system concept called tactile response and substructuring. The main focus is on managing the dynamic properties like vibration, noise, and harshness that occur during the operational mode. Tactile response is defined as the response of subsystem which is induced when a human body touches a vibrating system. Sub structuring is a computational method used to reduce the dynamic behavior of a large complex system with a smaller number of degrees of freedom without disturbing the mesh size of the model. Sub structuring has the… More >

Zongying Fu¹, Yongdong Zhou¹, Tingguo Yan², Yun Lu^1,*

Journal of Renewable Materials, Vol.11, No.1, pp. 93-102, 2023, DOI:10.32604/jrm.2023.021808

Abstract Drying crack is a common phenomenon occurring during moisture discharge from wood, reducing efficient wood utilization. Drying crack is primarily caused by drying stress, and the reasonable methods for determining drying stress are sparse. In this study, the initiation and propagation of cracks during wood discs drying were simulated using the extended finite element method (XFEM). The distribution of drying stress and displacement was analyzed at different crack conditions based on the simulation results. This study aimed to solve the problem of the limitation of drying stress testing methods and provide a new idea for the study of wood drying… More >

Ladislav Sator^1,*, Vladimir Sladek¹, Jan Sladek¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.24, No.1, pp. 1-1, 2022, DOI:10.32604/icces.2022.08679

Abstract The paper deals with transient analysis of homogeneous as well as FGM (functionally graded material) thin micro/nano plates subjected to transversal dynamic loading. within the highergrade continuum theory of elasticity. The microscopic structure of material is reflected in this higher-grade continuum theory via one material coefficient called the micro-length scale parameter. Furthermore the material can be composed of two micro-constituents what is included in the employed continuum model by functional gradation of the Young’s modulus through the plate thickness with assuming power-law dependence of volume fractions of micro-constituents on the transversal coordinate. The high order derivatives of field variables are… More >