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Experimental Investigation and Semi-Active Control Design of A Magnetorheological Engine Mount

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Sound & Vibration 2019年第6期53卷 297-308页

作者： Seyed Salman hosseini Javad Marzbanrad School of Automotive Engineering Iran University of Science and TechnologyTehranIran Faculty at School of Automotive Engineering Iran University of Science and TechnologyTehranIran

In this paper;the dynamic characteristics of a semi-active magnetorheological fluid(MRF)engine mount are *** do so,the performance of the MRF engine mount is experimentally examined in higher frequencies(50~170 Hz)and the various amplitudes(0.01~0.2 mm).In such an examination,an MRF engine mount along with its magnetically biased is fabricated and successfully *** addition,the natural frequencies of the system are obtained by standard hammer modal *** modelling the behavior of the system,a mass-spring-damper model with tuned PID coefficients based on Pessen integral of absolute error method is *** parameters of such a model including mass,damping ratio,and stiffness are identified with the help of experimental modal tests and the recursive least square method(RLS).It is shown that using PID controller leads to reducing the vibration transmissibility in the resonance frequency(=93.45 Hz)with respect to the typical passive engine mount by a factor of 58%.The average of the vibration transmissibility decreasing is also 43%within frequency bandwidth(50~170 Hz).

关键词： Semi-active engine mount PID controller experimental data least square method magnetorheological fluid

Land-use change and carbon stocks: A case study, Noor County, Iran

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Journal of Forestry Research 2013年第3期24卷 461-469页

作者： Niloufar Haghdoost Moslem Akbarinia Seyed Mohsen hosseini Department of Forestry Faculty of Natural Resources Tarbiat Modares UniversityNoor Mazandaran Iran. Postal code: 46417-76489 Department of Forestry Faculty of Natural Resources Tarbiat Modares UniversityNoor Mazandaran Iran

Land-use changes and land cover strongly influence carbon stock and distribution within ecosystems. Changing the land-use from natural forest to other land-uses has been more rapid in the past few decades than at any time in Iran＇s history. In this study, we investigated the effects of changing the land-use from natural forest to other land-uses on carbon stocks in northern Iran. We selected five sites for this study：（I） a natural forest, （II） an agricultural field and （III） plantations of three different species （Alnus subcordata .L, Acer velutinum .Boiss and Cu- pressus sempervirens）. We examined the effects of land-use changes on：（I） soil carbon stock （0-50 cm depth）, （II） biomass and carbon content of grassy vegetation and litter and （III） above- and below-ground biomass C in trees. Soil C stock was higher under A. velutinum and C. sempervirens whereas it was lower under A. subcordata and agricultural sites. Biomass and C content of grassy vegetation were significantly higher at A. veluti- num and C. sempervirens plantations. However, litter biomass and C content were significantly higher at the natural forest site. Natural forest had the highest amount of C content in above- and below-ground bio- mass. Total ecosystem C stocks declined following land-use changes.

关键词： biomass climate change mitigation Hyrcanian forests plan-tation soil organic carbon

A complex solution on the dynamic response of sandwich graphene-reinforced aluminum-based composite beams with copper face sheets under two moving constant loads on an elastic foundation

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International Journal of Mechanical System Dynamics 2023年第3期3卷 251-264页

作者： Mohammadreza Eghbali Seyed Amirhosein hosseini Department of Mechanical Engineering University of ZanjanZanjanIran Department of Industrial Mechanical and Aerospace EngineeringBuein Zahra Technical UniversityQazvinIran

An analytical solution was used to investigate the elastic response of a sandwich beam with a graphene-reinforced aluminum-based composite(GRAC)on an elastic foundation using copper as the face layer of the functionally graded composite beam and a simply supported boundary ***'s higher-order shear deformation theory was utilized to derive the equations,which were solved in Laplace space and then converted into space–time using Laplace *** exact response of the GRAC sandwich beam was obtained by considering the displacement at the mid-span of the sandwich *** moving loads with different speed ratios were applied at a single point,and the effect of various parameters,including the spring constant,the speed ratio,the percentage of graphene,the moving load speed,and the distribution pattern,was *** study aimed to eliminate any overlap and improve the accuracy of the *** exact solving method presented has not been reported in other articles so ***,due to the difficulty of solving mathematical equations,this method is only applicable to simple boundary conditions.

关键词： GRAC beams moving load Laplace transform elastic foundation analytical solution aluminum-based

Static and dynamic responses of a microcantilever with a T-shaped tip mass to an electrostatic actuation

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Acta Mechanica Sinica 2016年第6期32卷 1104-1122页

作者： B.Firouzi M.Zamanian S.A.A.hosseini Department of Mechanical Engineering Faculty of Engineering Kharazmi University

In this study, nonlinear static and dynamic responses of a microcantilever with a T-shaped tip mass excited by electrostatic actuations are investigated. The electrostatic force is generated by applying an electric voltage between the horizontal part of T-shaped tip mass and an opposite electrode plate. The cantilever microbeam is modeled as an Euler-Bernoulli beam. The T-shaped tip mass is assumed to be a rigid body and the nonlinear effect of electrostatic force is considered. An equation of motion and its associated boundary conditions are derived by the aid of combining the Hamilton principle and Newton’s method. An exact solution is obtained for static deflection and mode shape of vibration around the static position. The differential equation of nonlinear vibration around the static position is discretized using the Galerkin method. The system mode shapes are used as its related comparison functions. The discretized equations are solved by the perturbation theory in the neighborhood of primary and subharmonic resonances. In addition, effects of mass inertia, mass moment of inertia as well as rotation of the T-shaped mass, which were ignored in previous works, are considered in the analysis. It is shown that by increasing the length of the horizontal part of the T-shaped mass, the amount of static deflection increases, natural frequency decreases and nonlinear shift of the resonance frequency increases. It is concluded that attaching an electrode plate with a T-shaped configuration to the end of the cantilever microbeam results in a configuration with larger pull-in voltage and smaller nonlinear shift of the resonance frequency compared to the configuration in which the electrode plate is directly attached to it.

关键词： MEMS Electrostatic Static deflection Natural frequency Pull-in voltage Perturbation theory T-shaped mass Primary and subharmonic resonances

Geometrically Nonlinear Analysis of Structures Using Various Higher Order Solution Methods: A Comparative Analysis for Large Deformation

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Computer Modeling in Engineering & Sciences 2019年第12期121卷 877-907页

作者： Ali Maghami Farzad Shahabian Seyed Mahmoud hosseini Civil Engineering Department Faculty of EngineeringFerdowsi University of MashhadMashhadIran Industrial Engineering Department Faculty of EngineeringFerdowsi University of MashhadMashhadIran

The suitability of six higher order root solvers is examined for solving the nonlinear equilibrium equations in large deformation analysis of *** applied methods have a better convergence rate than the quadratic Newton-Raphson *** six methods do not require higher order derivatives to achieve a higher convergence *** algorithms are developed to use the higher order methods in place of the Newton-Raphson method to solve the nonlinear equilibrium equations in geometrically nonlinear analysis of *** higher order methods are applied to both continuum and discrete problems(spherical shell and dome truss).The computational cost and the sensitivity of the higher order solution methods and the Newton-Raphson method with respect to the load increment size are comparatively *** numerical results reveal that the higher order methods require a lower number of iterations that the Newton-Raphson method to *** is also shown that these methods are less sensitive to the variation of the load increment *** it is indicated in numerical results,the average residual reduces in a lower number of iterations by the application of the higher order methods in the nonlinear analysis of structures.

关键词： Geometrically nonlinear analysis higher order methods predictor-corrector algorithms convergence rate sensitivity to the increment size

Seismic assessment of nature-inspired hexagrid lateral load-resisting system

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Earthquake Engineering and Engineering Vibration 2021年第3期20卷 661-672页

作者： Yasaman Memarzadeh Kiani Seyed Hossein hosseini Lavassani Afshin Meshkat-Dini Department of Civil Engineering Faculty of EngineeringKharazmi UniversityTehranIran

This paper provides a general perspective of the seismic performance of a nature-inspired,honey-comb grid structural system,known as a hexagrid,under near-field ground *** performance of this skeleton is then compared to that of a bundled-tube,as a conventional and efficient load-resisting system in order to provide a better perception of the seismic behavior of a hexagrid *** 20-story buildings with bundled-tube and hexagrid skeleton were *** behavior of the structures was investigated through 3-D finite element computer models and nonlinear time history analyses by subjecting the models to seven three-component records of scaled near-field ground *** of peak inter story drift and corner beam-column joint rotations were calculated and *** indicated that by replacing the exterior columns of the bundled-tube system with inclined beam-column elements of nature-inspired hexagons,lateral stiffness of the building increased and it would tolerate less deformations before global dynamic instability is *** presence of inclined columns in the hexagrid skeleton helped to concentrate local nonlinearities in ring beams rather than exterior columns.

关键词： high-rise steel structure hexagrid structure performance assessment nonlinear seismic analysis

Formation of Nano/Ultrafine Grains in AISI 321 Stainless Steel Using Advanced Thermo-Mechanical Process

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Acta Metallurgica Sinica(English Letters) 2015年第4期28卷 499-504页

作者： Mohsen Golzar Shahri S.Rahman hosseini Mehdi Salehi Department of Materials Engineering Isfahan University of Technology Department of Materials Engineering Maleke-Ashtar University of Technology

Production of nano/ultrafine grains through deformation-induced martensite formation and its reversion to austenite in an AISI 321 stainless steel was studied. The repetitive cold rolling and subsequent annealing were conducted to obtain nanocrystalline structure. Heavy cold rolling （90% reduction） at ＋20 and -20 ℃ was carded out to induce the formation of α′-martensite from metastable austenitic material. The process was followed by annealing treatment at 700-900 ℃ for 0.5-30 min. Effects of process parameters, i.e., ＂reduction percentage,＂＂rolling temperature,＂＂annealing temperature＂ and ＂annealing time＂, on the microstructural development were considered. Microstructural evolutions were conducted using feritscope, X-ray diffractometer and scanning electron microscope. Hardness of the specimens was measured by Vickers method. Results revealed that the higher thickness reduction and lower rolling temperature provided more martensite volume fraction and further hardness. X-ray diffraction patterns and feritoscopic results indicated that saturated strain （εs） was reduced from 2.3 to 0.9 when temperature declined from ＋20 to -20 ℃. The smallest grain size （about 70 nm） was achieved in the condition of cold rolling at -20℃followed by annealing at 750 ℃for 5 min.

关键词： Austenitic stainless steel Deformation-induced martensite Nano/ultrafine grain structure Thermo-mechanical treatment

Mathematical model and energy analysis of ethane dehydration in two-layer packed-bed adsorption

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Particuology 2019年第6期17卷 33-40页

作者： Yadollah Tavan Seyyed Hossein hosseini Goodarz Ahmadi Martin Olazar Chemical and Petroleum Engineering Department Sharif University of TechnologyAzadi Av.TehranIran Chemical Engineering Department Faculty of EngineeringIlam University69315-516 IlamIran Department of Mechanical and Aeronautical Engineering Clarkson UniversityPotsdamNY 13699-5725USA Department of Chemical Engineering Faculty of Science and TechnologyUniversity of the Basque CountryP.O.Box 64448080 BilbaoSpain

The 3A zeolites are excellent adsorbents for industrial-scale gas dehydration because of the low energy required for regeneration and ease of operation.A computational study of the dehydration of an industrial feed stream containing ethane and water was performed using an in-house code that included an appropriate equilibrium adsorption *** validated computational model was used to examine the impact of particle size on the process dynamics and the corresponding pressure *** water concentration along the adsorption column was also *** increase the process capacity,the packed adsorption bed was divided into two distinct layers,which were operated with different particle *** length of each layer was determined by a parametric *** best breakthrough time,i.e.,107,800 s,at the allowed pressure drop was obtained when the lengths of the first and second layers were 4.5 and 1 m,*** results showed that the new two-layer adsorption bed could save around 33.8%in total energy requirement in comparison to that of a single bed.

关键词： Molecular sieve Breakthrough Adsorption Ethane dehydration Mathematical model

Thermo-magnetic analysis of thick-walled spherical pressure vessels made of functionally graded materials

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Applied Mathematics and Mechanics(English Edition) 2019年第6期40卷 751-766页

作者： M. A. NEMATOLLAHI A. DINI M. hosseini Department of Biosystems Engineering College of AgricultureShiraz UniversityShiraz 71441-65186Iran Department of Mechanical Engineering Ferdowsi University of MashhadMashhad 91775-1111Iran Department of Mechanical Engineering Sirjan University of TechnologySirjan 78137-33385Iran

This study presents an analytical solution of thermal and mechanical displacements, strains, and stresses for a thick-walled rotating spherical pressure vessel made of functionally graded materials (FGMs). The pressure vessel is subject to axisymmetric mechanical and thermal loadings within a uniform magnetic field. The material properties of the FGM are considered as the power-law distribution along the thickness. Navier’s equation, which is a second-order ordinary differential equation, is derived from the mechanical equilibrium equation with the consideration of the thermal stresses and the Lorentz force resulting from the magnetic field. The distributions of the displacement, strains, and stresses are determined by the exact solution to Navier’s equation. Numerical results clarify the influence of the thermal loading, magnetic field, non-homogeneity constant, internal pressure, and angular velocity on the magneto-thermo-elastic response of the functionally graded spherical vessel. It is observed that these parameters have remarkable effects on the distributions of radial displacement, radial and circumferential strains, and radial and circumferential stresses.

关键词： analytical solution magnetic field thermal loading rotating thick-walled spherical pressure vessel functionally graded material (FGM)