International Journal of Computational Materials Science and Engineering

The purpose of this study is to determine the natural frequencies of functionally graded (FG) porous circular plates while taking into account the uniform and nonuniform porosity distribution in the thickness direction. The material properties of FG plates are assumed to be varying continuously in the thickness direction. The material properties are calculated based on Voigt’s micro-mechanical model taking power law distribution method with arbitrary power index. The mathematical model of the FG circular porous plate is based on the first-order shear deformation theory (FSDT). The motion of equations is derived using Hamilton’s energy principle and the Differential Quadrature Method (DQM) is applied to solve this equation. Convergence studies with respect to the number of nodes are used to validate the established solution methodology for nondimensional frequencies of FG circular plates. The nondimensional frequency for the FG circular plate is calculated and compared to the existing literature results. The effects of the thickness to radius ratio, material parameters, porosity distribution, and boundary conditions on the fundamental frequency for FG porous circular plates are also discussed in detail.

The problems of elastic wave propagation in the micropolar porous materials have been attempted under the interaction of micro-rotation tensor and porous distribution in this material. We obtain the existence of three coupled longitudinal and two coupled shear waves propagating with different phase speeds. Numerically, the phase speed and attenuation of five basic waves are computed. We consider the incident plane waves at the boundary of micropolar porous materials, then the dispersive nature of the incident waves is studied and the existence of critical angle for the incident shear wave is found. The amplitude and energy ratios of various reflected waves for the incident coupled longitudinal and shear waves are obtained analytically and numerically. Further, the influence of different material parameters is studied using dispersion relation and the relevant numerical values.

The non-Darcian flow and solute transport in geometrically nonlinear porous media are modeled with Riesz derivative solved via Simpson’s rule or treated through the Grünwald–Letnikow definition and subsequently discretized via Finite Difference schemes when considering anomalous diffusion, nonlinear diffusion, or anomalous solute advection–dispersion, respectively. Particularly, the standard diffusion and advection–dispersion equations are converted into fractional equations to take into account memory effects as well as non-Fickian dispersion processes. Hence, a 3D hydro-mechanical model accounting for geometric nonlinearities is correspondingly developed including the fractional diffusion–advection–dispersion equations (FRADEs) and a series of one-dimensional analyses are performed with validation purposes.

Purpose: In this work, the influences of different field operating parameters (pH and partial pressure of H₂S) and crack types (isolated and cluster cracks) are investigated on the distribution of hydrogen concentration in pipeline steel. Design/methodology/approach: A numerical simulation based on the finite element method was performed using the COMSOL Multiphysics software to achieve the objectives. Findings: Hydrogen concentration and total hydrogen flux are increased when pH decreases and $p_{H_{2}S}$ increases. Besides, the crack flanks are the most appropriate areas for hydrogen diffusion. Accordingly, the areas including step-wise cracking absorb more atomic hydrogen, and the space between the upper surface of the crack and the outer wall is no longer protected. Furthermore, the computational results reveal how a blister on the top of a cluster crack can be crucial by providing enough area for hydrogen to diffuse, and the area between the crack top surface and the outer wall could no longer be protected from hydrogen flux.

Originality: Evaluation of hydrogen concentration in different areas of isolated and cluster cracks under different field operating conditions (pH and $p_{H_{2}S})$ is not yet understood, which is discussed in this study.

Molecular dynamics (MD) simulations permit copying methodical differences of mechanical and interfacial properties outside the scope of experimental approaches. This paper reviews the effect of graphene on the mechanical properties such as Young’s modulus, shear modulus, ultimate tensile strength and Young’s modulus of epoxy nanocomposites via MD simulations. In MD simulation arrangement, the computational techniques are studied for dissimilar qualities of mixing a polymer matrix with graphene as the nanofiller. Subsequently, numerous papers are discussed involving graphene and its polymer nanocomposites. Furthermore, advances in molecular modeling, simulation of graphene and their nanocomposites are deliberated by considering feature charge graphene assemblies, aspect ratio, weight fraction, atomic density, molecular energy and density effect as the primary factors. It was concluded from investigations that their mechanical properties as well as interfacial properties are suitable for scientific applications.

The present investigation reports on the thermal conductivity of areca fiber and coconut shell particulate (CSP)-reinforced polymer composites. The fiber and particulate reinforcement percentages were 10–40wt.% with various weight ratios as 1:1, 1:3, and 3:1. The main focus has been given to the development of a micromechanical model to calculate the effective thermal conductivity of areca fiber and CSP-reinforced hybrid composites. In the numerical study, steady-state one-dimensional heat conduction analysis is performed with a periodic arrangement of cylinders and spherical reinforcement using ANSYS software. Unitherm ${}^{\text{TM}}$Model 2022 equipment was used to measure the experimental thermal conductivity values of the hybrid composite materials and validated with the micromechanical and numerical values. The experimental results attained for thermal conductivity are supported by the proposed micromechanical model. The measured values of the composites were found to be in very close agreement with the micromechanical model and the numerical analysis. It is concluded from this study that the addition of areca fiber and CSP improves the thermal insulation capability of neat epoxy.