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Applied Mathematics and Mechanics(English Edition) 2021年第2期42卷 209-222页

作者： Yong YANG S.SAHMANI b.safaei School of Civil Engineering Guangzhou UniversityGuangzhou 510006China Mechanical Rotating Equipment Department Niroo Research Institute(NRI)Tehran 14665-517Iran Department of Mechanical Engineering Eastern Mediterranean UniversityFamagusta 99628North Cyprus via Mersin 10Turkey

The size-dependent geometrically nonlinear harmonically soft excited oscillation of composite truncated conical microshells(CTCMs)made of functionally graded materials(FGMs)integrated with magnetostrictive layers is *** is supposed that the FGM CTCMs are subjected to mechanical soft excitations together with external magnetic *** analytical framework is created by a microstructuredependent shell model having the 3rd-order distribution of shear deformation based on the modified couple stress(MCS)continuum *** the aid of the discretized form of differential operators developed via the generalized differential quadrature technique,a numerical solution methodology is introduced for obtaining the couple stress-based amplitude and frequency responses related to the primary resonant dynamics of the FGM *** phenomena due to the loss of the first stability branch and falling down to the lower stable branch can be seen in the nonlinear primary resonance of the FGM *** is demonstrated that the hardening type of nonlinearity results in bending the frequency response to the right side,and the MCS type of size effect weakens this ***,for higher material gradient indexes,the hardening type of nonlinearity is enhanced,and the MCS-based frequency response bends more considerably to the right side.

关键词： truncated conical shell size dependency functionally graded composite nonlinear resonance piezo-magnetic material

Isogeometric nonlocal strain gradient quasi-three-dimensional plate model for thermal postbuckling of porous functionally graded microplates with central cutout with different shapes

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Applied Mathematics and Mechanics(English Edition) 2021年第6期42卷 771-786页

作者： Rui SONG S.SAHMANI b.safaei Department of Civil and Architecture Engineering Nanchang Institute of TechnologyNanchang 330099China Mechanical Rotating Equipment Department Niroo Research Institute(NRI)Tehran 14665-517Iran Department of Mechanical Engineering Easten Mediterranean UnivensityFamagusta 99628North Cyprus via Mersin 10Turkey

This study presents the size-dependent nonlinear thermal postbuckling characteristics of a porous functionally graded material(PFGM) microplate with a central cutout with various shapes using isogeometric numerical technique incorporating nonuniform rational b-splines. To construct the proposed non-classical plate model, the nonlocal strain gradient continuum elasticity is adopted on the basis of a hybrid quasithree-dimensional(3D) plate theory under through-thickness deformation conditions by only four variables. by taking a refined power-law function into account in conjunction with the Touloukian scheme, the temperature-porosity-dependent material properties are extracted. With the aid of the assembled isogeometric-based finite element formulations,nonlocal strain gradient thermal postbuckling curves are acquired for various boundary conditions as well as geometrical and material parameters. It is portrayed that for both size dependency types, by going deeper in the thermal postbuckling domain, gaps among equilibrium curves associated with various small scale parameter values get lower, which indicates that the pronounce of size effects reduces by going deeper in the thermal postbuckling regime. Moreover, we observe that the central cutout effect on the temperature rise associated with the thermal postbuckling behavior in the presence of the effect of strain gradient size and absence of nonlocality is stronger compared with the case including nonlocality in absence of the strain gradient small scale effect.

关键词： porosity functionally graded(FG)composite isogeometric approach quasi-three-dimensional(3D)plate theory nonlocal strain gradient elasticity

Size-dependent shear buckling response of FGM skew nanoplates modeled via different homogenization schemes

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Applied Mathematics and Mechanics(English Edition) 2020年第4期41卷 587-604页

作者： Yuan YUAN KeZHAO S.SAHMANI b.safaei School of Mechanical and Precision Instrument Engineering Xi’an University of TechnologyXi’an 710048China School of Science and Technology The University of GeorgiaTbilisi 0171Georgia School of Mechanical Engineering Eastern Mediterranean UniversityG.MagosaTRNC Mersin 10Turkey

The size effects on the shear buckling behaviors of skew nanoplates made of functionally graded materials(FGMs)are *** material properties are supposed to be changed uniformly from the ceramic phase to the metal one along the plate *** estimate the associated effective material properties,various homogenization schemes including the Reuss model,the Voigt model,the Mori-Tanaka model,and the Hashin-Shtrikman bound model are *** nonlocal elasticity theory together with the oblique coordinate system is applied to the higher-order shear deformation plate theory to develop a size-dependent plate model for the shear buckling analysis of FGM skew *** Ritz method using Gram-Schmidt shape functions is used to solve the size-dependent *** is found that the significance of the nonlocality in the reduction of the shear buckling load of an FGM skew nanoplate increases for a higher value of the material property gradient ***,by increasing the skew angle,the critical shear buckling load of an FGM skew nanoplate *** pattern becomes a bit less significant for a higher value of the material property gradient ***,among various homogenization models,the Voigt and Reuss models in order estimate the overestimated and underestimated shear buckling loads,and the difference between them reduces by increasing the aspect ratio of the skew nanoplate.

关键词： microstructure functionally graded material(FGM) Ritz method shear buckling nonlocal theory of elasticity

Nonlinear free vibrations of porous composite microplates incorporating various microstructural-dependent strain gradient tensors

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Applied Mathematics and Mechanics(English Edition) 2022年第6期43卷 825-844页

作者： Duquan ZUO b.safaei S.SAHMANI Guoling MA Aviation Engineering College Civil Aviation Flight University of ChinaGuanghan 618307Sichuan ProvinceChina Chongqing Engineering Research Center for Advanced Intelligent Manufacturing Technology Chongqing Three Gorges UniversityChongqing 404100China Department of Mechanical Engineering Eastern Mediterranean UniversityFamagusta 99628North Cyprus via Mersin 10Turkey School of Science and Technology The University of GeorgiaTbilisi 0171Georgia

The main objective of the present numerical analysis is to predict the nonlinear frequency ratios associated with the nonlinear free vibration response of porous composite plates at microscale in the presence of different microstructural gradient *** achieve this end,by taking cubic-type elements into account,isogeometric models of porous composite microplates are obtained with and without a central cutout and relevant to various porosity patterns of distribution along the plate *** established unconventional models have the capability to capture the effects of various unconventional gradient tensors continuity on the basis of a refined shear deformable plate *** the simply supported microsized uniform porous functionally graded material(UPFGM)plate having the oscillation amplitude equal to the plate thickness,it is revealed that the rotation gradient tensor causes to reduce the frequency ratio about 0.73%,the dilatation gradient tensor causes to reduce it about 1.93%,and the deviatoric stretch gradient tensor leads to a decrease of it about 5.19%.On the other hand,for the clamped microsized U-PFGM plate having the oscillation amplitude equal to the plate thickness,these percentages are equal to 0.62%,1.64%,and 4.40%,***,it is found that by changing the boundary conditions from clamped to simply supported,the effect of microsize on the reduction of frequency ratio decreases a bit.

关键词： size dependency isogeometric approach nonlinear dynamics geometric approximation micromechanics

A highly flexible green synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives with CuI nanoparticles as catalyst under solvent-free conditions

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Chinese Chemical Letters 2014年第3期25卷 401-405页

作者： Javad safaei-Ghomi Hossein Shahbazi-Alavi Abolfazl Ziarati Raheleh Teymuri Mohammad Reza Saberi Department of Organic Chemistry Faculty of ChemistryUniversity of Kashan

CuI nanoparticles as an efficient catalyst have been used for the preparation of 1H-pyrazolo[l,2- b]phthalazine-5,10-diones by the four-component condensation reaction of phthalic anhydride, hydrazine monohydrate, aromatic aldehydes and malononitrile or ethyl cyanoacetate under solvent- free conditions in good to excellent yields, short reaction times and environmentally benign, milder reaction conditions.

关键词： NanoparticlesMulti-component reactionsSolvent-freePyrazolophthalazine

Q-switched fiber laser using carbon platinum saturable absorber on side-polished fiber

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Chinese Optics Letters 2017年第9期15卷 46-50页

作者： H.Ahmad H.Hassan R.safaei K.Thambiratnam I.S.Amiri Photonics Research Centre University of MalayaKuala Lumpur 50603Malaysia

A 1550 nm Q-switched fiber laser using a carbon platinum saturable absorber deposited on side-polished fiber（SPF） is proposed and demonstrated. The SPF is approximately 2 mm with a polarization-dependent loss（PDL）of 0.4 db and an insertion loss of 2.5 db. A stable Q-switched output spectrum is obtained at 1559.34 nm with a peak power of ~6 mW, a pulse width of 1.02 μs, pulse energy of 5.8 nJ, average output power of 0.76 mW, and a repetition rate of 131.6 kHz taken at a pump power of 230.0 mW. A signal-to-noise ratio of 49.62 d b indicates that the Q-switched pulse is highly stable.

关键词： SPF Q-switched fiber laser using carbon platinum saturable absorber on side-polished fiber