Elastic wave propagation analysis in sandwich nanoplate assuming size effects

Amir Behshad,Maryam Shokravi,Akbar Shafiei Alavijeh,Hamed Karami 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.1

This paper presents a study on the wave propagation of functionally graded material (FGM) sandwich nanoplates with soft core resting on a Winkler foundation. The structure is modelled by classical theory. Motion equations are derived by the assumption of nonlocal Eringen theory and energy method. Then, the equations are solved using an exact method for finding phase velocity responses. The effects of Winkler foundation, nonlocal parameters, thickness and mode number on the dispersion of elastic waves are shown. With the increase of spring constant, the speed of wave propagation increases and reaches a uniform state at a higher wave number.

The effect of a non-uniform pulse-width modulated magnetic field with different angles on the swinging ferrofluid droplet formation

Mohamad Ali Bijarchi,Amirhossein Favakeh,Mohammad Behshad Shafii 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.84 No.-

In this study, ferrofluid droplet formation from a nozzle in the presence of a non-uniform Pulse-WidthModulated (PWM) magneticfield with different angles was studied experimentally. A Drop-on-Demandplatform was introduced and three different regimes of droplet formation were observed. The regimemap of the droplet formation was presented. A new type of droplet formation evolution was observed inwhich the droplet is formed while it is swinging around the nozzle, and the satellite droplet is notgenerated in this regime. The effects offive important parameters including magneticflux density,applied magnetic frequency, duty cycle, distance between the nozzle and the center of the upper surfaceof the coil, and the angle of magnetic coil with respect to gravity on droplet diameter, formationfrequency, number of pulses for one droplet generation, and droplet formation evolution wereinvestigated. Results demonstrated that by increasing the magneticflux density and duty cycle, and bydecreasing applied magnetic frequency, the droplet diameter decreases, whereas the formationfrequency increases. Also, the minimum droplet diameter was observed at the distance of 10 mm and theangle of 45 . Finally, a correlation for dimensionless droplet diameter was proposed with an averagerelative error of 2.8%.

Frequency response of elastic nanocomposite beams containing nanoparticles based on sinusoidal shear deformation beam theory

Suxia Hou,Shengbin Wu,Jijun Luo,Mohsen Nasihatgozar,Amir Behshad 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.45 No.4

Improving the mechanical properties of concrete in the construction industry in order to increase resistance to dynamic and static loads is one of the essential topics for researchers. In this work, vibration analysis of elastic nanocomposite beams reinforced by nanoparticles based on mathematical model is presented. For modelling of the strucuture, sinusoidal shear deformation beam theory (SSDBT) is utilized. Mori-anak model model is utilized for obtaining the effective properties of the strucuture including agglomeration influences. Utilizing the energy method and Hamilton’s principal, the motion equations are calculated. The frequency of the elastic nanocomposite beam is obtanied by analytical method. The aim of this work is investigating the effects of nanoparticles volume percent and agglomeration, length and thickness of the beam on the frequency of the structure. The results show that the with enhancing the nanoparticles volume percent, the frequency is increased. In addition, the water absorption of the concrete is presented in this article.

Dynamic analysis of viscoelastic concrete plates containing nanoparticle subjected to low velocity impact load

Luo, Jijun,Lv, Meng,Hou, Suxia,Nasihatgozar, Mohsen,Behshad, Amir Techno-Press 2022 Advances in nano research Vol.13 No.4

Dynamic study of concrete plates under impact load is presented in this article. The main objective of this work is presenting a mathematical model for the concrete plates under the impact load. The concrete plate is reinforced by carbon nanoparticles which the effective material proprieties are obtained by mixture's rule. Impacts are assumed to occur normally over the top layer of the plate and the interaction between the impactor and the structure is simulated using a new equivalent three-degree-of-freedom (TDOF) spring-mass-damper (SMD) model. The structure is assumed viscoelastic based on Kelvin-Voigt model. Based on the classical plate theory (CPT), energy method and Hamilton's principle, the motion equations are derived. Applying DQM, the dynamic deflection and contact force of the structure are calculated numerically so that the effects of mass, velocity and height of the impactor, volume percent of nanoparticles, structural damping and geometrical parameters of structure are shown on the dynamic deflection and contact force. Results show that considering structural damping leads to lower dynamic deflection and contact force. In addition, increasing the volume percent of nanoparticles yields to decreases in the deflection.

Investigation of hyperbolic dynamic response in concrete pipes with two-phase flow

Zheng, Chuanzhang,Yan, Gongxing,Khadimallah, Mohamed Amiine,Nouri, Alireza Zamani,Behshad, Amir Techno-Press 2022 Advances in concrete construction Vol.13 No.5

The objective of this study is to simulate the two-phase flow in pipes with various two-fluid models and determinate the shear stress. A hyperbolic shear deformation theory is used for modelling of the pipe. Two-fluid models are solved by using the conservative shock capturing method. Energy relations are used for deriving the motion equations. When the initial conditions of problem satisfied the Kelvin Helmholtz instability conditions, the free-pressure two-fluid model could accurately predict discontinuities in the solution field. A numerical solution is applied for computing the shear stress. The two-pressure two-fluid model produces more numerical diffusion compared to the free-pressure two-fluid and single-pressure two-fluid models. Results show that with increasing the two-phase percent, the shear stress is reduced.

Electro-thermo-mechanical stress analysis of smart sandwich cylindrical shell

Yuhua Zhou,Mohamed Amine Khadimallah,Seyedmahmoodreza Allahyari,Amir behshad 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.40 No.5

In this paper, stress analysis of a multi-walled hollow cylinder made from a functionally graded material (POLYMER) sandwiched between two piezoelectric layers is investigated. This system is subjected to internal and external pressure, a distributed temperature field due to steady state heat conduction with convective boundary condition, and a constant potential difference imposed on piezoelectric layers between its inner and outer surfaces or combination of these loadings. All mechanical and thermal properties except for the Poisson’s ratio of Polymer layer are assumed to be power functions of the radial position. Using equilibrium equations, stress-strain relations and electromechanical coupling of piezoelectric layer, the constitutive differential equation in term of radial displacement is obtained. Considering electro-mechanical boundary conditions, this differential equation is analytically solved. The electro-thermo-mechanical stresses, electric potential and radial displacement distributions in three layers are obtained.

Numerical simulation of the flow in pipes with numerical models

Hongjie Gao,Xinyu Li,Abdolreza Hooshmandi Nezhad,Amir Behshad 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.81 No.4

The objective of this study is to simulate the flow in pipes with various boundary conditions. Free-pressure fluid model, is used in the pipe based on Navier-Stokes equation. The models are solved by using the numerical method. A problem called “stability of pipes” is used in order to compare frequency and critical fluid velocity. When the initial conditions of problem satisfied the instability conditions, the free-pressure model could accurately predict discontinuities in the solution field. Employing nonlinear strains-displacements, stress-strain energy method the governing equations were derived using Hamilton's principal. Differential quadrature method (DQM) is used for obtaining the frequency and critical fluid velocity. The results of this paper are analyzed by hyperbolic numerical method. Results show that the level of numerical diffusion in the solution field and the range of well-posedness are two important criteria for selecting the two-fluid models. The solutions for predicting the flow variables is approximately equal to the two-pressure model 2. Therefore, the predicted pressure changes profile in the twopressure model is more consistent with actual physics. Therefore, in numerical modeling of gas-liquid two-phase flows in the vertical pipe, the present model can be applied.

Modeling of laser thermal and hydrodynamic effects on a dilute suspension of micro-particles in water

Mohammad Zabetian,Mohammad Hassan Saidi,Mohammad Said Saidi,Mohammad Behshad Shafii 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.3

Particle manipulation using laser beam is almost a new and contactless technique in particulate sciences. The method is based on theradiation pressure of light photons on the particles suspended in a semi-transparent fluid. Applications of the technique mainly covermicroscopic separation and detection of biological objects. In this work, a theoretical study is conducted to investigate the hydrodynamicand thermal effects on a particulate flow in a mini-channel. Laser thermal effects are studied as a result of light absorption either in fluidor dispersed phase. An analytical model is developed to be the real simulator of a test bed developed by the authors. The main objectiveof performed simulation is to determine the conditions of hydrodynamic laser-particle interaction and the contribution of thermal effects. More specifically, the criteria for size of particles and beam parameters to meet the mentioned conditions are presented. The model resultsare used for design and selection of elements in a particle manipulation system.