Person: Aghazadeh, Reza
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Doç. Dr.
Last Name
Aghazadeh
First Name
Reza
Name
Reza AGHAZADEH
13 results
Filters
Advanced Search
Filter by
Settings
Search Results
Now showing 1 - 10 of 13
Publication Torsional dynamics of bi-directional functionally graded small-scale tubes possessing a variable length scale parameter(TAYLOR & FRANCIS INC, 2022) Aghazadeh, Reza; Aghazadeh, Reza; Turkish Aeronautical Association; Turk Hava Kurumu UniversityThe aim of the current study is to investigate torsional vibrations of bi-directional functionally graded (FG) small-scale tubes. The size effect is captured using the modified couple stress theory (MCST). Through-the-thickness distribution profile of material properties are characterized by employing a power-law function, which incorporates a gradation index,beta, and longitudinal varation in material properties is featured by an exponential function which employs a gradient parameter,alpha. Similar to other material properties, continuous spatial variation of the length scale parameter is also incorporated into the analysis of two-dimensionally FG tubes. The model, including governing equations of motion and boundary conditions, is developed through the utilization of Hamilton's principle. By employing differential quadrature method (DQM) numerical results regarding torsional vibrations are provided. Accuracy of the proposed model and procedures are verified through verification comparisons made to limiting cases available in the literature. Numerical results reveal effects of various material and geometric parameters on natural frequencies and indicate that torsional free vibration characteristics of small-sized tubes are sensitive to distribution profile of constituents, geometric aspect ratios and effective length scale parameter. Results also demonstrate that length scale parameter variation has significant influence on natural frequencies which justifies the necessity of its consideration in analyses.Publication Static and free vibration analyses of small-scale functionally graded beams possessing a variable length scale parameter using different beam theories(Elsevier BV, 2014-07) Reza Aghazadeh; Ender Cigeroglu; Serkan Dag; Aghazadeh, RezaPublication Dynamics of axially functionally graded pipes conveying fluid using a higher order shear deformation theory(International Advanced Researches and Engineering Journal, 2021-08-15) Reza AGHAZADEH; Aghazadeh, RezaThis study presents a novel approach for addressing dynamical characteristics of fluid conveying axially functionally graded pipes. The variation of material properties of the pipe along axial direction is taken into account according to a power-law function. Owing to a unified expression for displacement field, the developed model can be recast into classical Euler – Bernoulli and Timoshenko tube models as well as a newly developed higher order shear deformable tube model; the latter satisfies zero-shear conditions on free surfaces, and hence yields more realistic results. The system of partial differential equations governing dynamics of fluid conveying axially functionally graded pipes is derived through utilization of Hamilton’s principle. Differential quadrature scheme is used to discretize the system of differential equations and generate numerical results. Detailed numerical investigations of the current fluid-solid interaction problem elucidate the effects of material gradation pattern, transverse shear deformation distribution profile along radial direction and fluid velocity on the natural frequencies of fluid conveying functionally graded pipes. The critical fluid velocity, which is a significant design parameter, can also be determined by means of developed procedures in this study.Publication Thermal effect on bending, buckling and free vibration of functionally graded rectangular micro-plates possessing a variable length scale parameter(Springer Science and Business Media LLC, 2018-02-08) Reza Aghazadeh; Serkan Dag; Ender Cigeroglu; Aghazadeh, RezaPublication Stability Analysis of Fluid Conveying Axially Functionally Graded Micro-Pipes Using a Refined Tube Model(Springer Science and Business Media LLC, 2022-01-04) Reza Aghazadeh; Aghazadeh, RezaPublication Thermal effect on bending, buckling and free vibration of functionally graded rectangular micro-plates possessing a variable length scale parameter(SPRINGER HEIDELBERG, 2018) Aghazadeh, Reza; Dag, Serkan; Cigeroglu, Ender; Aghazadeh, Reza; Middle East Technical University; Turk Hava Kurumu University; Turkish Aeronautical AssociationModified couple stress based model is presented to investigate statics, dynamics and stability of functionally graded micro-plates subjected to mechanical and thermal loadings. The features of FGM micro-plate including length scale parameter of modified couple stress theory assumed to be graded across the thickness by varying volume fractions of constituents. The governing equations of motion and boundary conditions are derived by means of Hamilton's principle. Displacement field is expressed in a unified way capable of producing results on the base of Kirchhoff, Mindlin, and third order shear deformation theories. The system of equations is solved numerically by implementing differential quadrature method. Verification studies are carried out by comparing the results of special cases to those available in the literature. Further numerical results regarding static thermal bending, natural frequencies and critical buckling loads of micro-plates undergoing uniform temperature change are provided. Presented numerical results clearly illustrate size effect at micro-scale, impact of length scale parameter variations and influence of initial thermal displacements and stresses upon mechanical behavior of functionally graded rectangular micro-plates.Publication Torsional dynamics of bi-directional functionally graded small-scale tubes possessing a variable length scale parameter(Informa UK Limited, 2020-08-27) Reza Aghazadeh; Aghazadeh, RezaPublication Tracking free surface and estimating sloshing force using image processing(Elsevier BV, 2017-11) Ufuk Tosun; Reza Aghazadeh; Cüneyt Sert; Mehmet Bülent Özer; Aghazadeh, RezaPublication Material gradation effects on twisting statics of bi-directional functionally graded micro-tubes(AIP Publishing, 2024-02-01) Reza Aghazadeh; Mohammad Rafighi; Raman Kumar; Mohammed Al Awadh; Aghazadeh, RezaThis study aims to characterize the twisting behavior of bi-directional functionally graded (FG) micro-tubes under torsional loads within the modified couple stress theory framework. The two material properties involved in the torsional static model of FG small-scale tubes, i.e., shear modulus and material length scale parameter, are assumed to possess smooth spatial variations in both radial and axial directions. Through the utilization of Hamilton’s principle, the governing equations and boundary conditions are derived, and then, the system of partial differential equations is numerically solved by using the differential quadrature method. A verification study is conducted by comparing limiting cases with the analytical results available in the literature to check the validity of the developed procedures. A detailed study is carried out on the influences of the phase distribution profile and geometric parameters upon twist angles and shear stresses developed in FG micro-tubes undergoing external distributed torques.Publication The Effects of Gravity and Material Gradation on the Stability of Axially Functionally Graded Cantilevered Pipes Conveying Fluid(CHINESE SOC MECHANICAL ENGINEERS, 2022) Aghazadeh, Reza; Aghazadeh, Reza; Turkish Aeronautical Association; Turk Hava Kurumu UniversityThis study deals with the dynamic problem of axially functionally graded (AFG) fluid conveying cantilevered pipes (FCCPs) aiming at improving stability of such fluid structure interaction systems. The model presented in the current paper also involves the effects of gravity. All material properties of the pipe assumed to be power-law functions of axial coordinate by incorporating a gradient index parameter. By choosing an appropriate value of gradient index different material distribution profiles such as homogeneous, linear, and nonlinear can be achieved. The model, comprised of equation of motion and boundary conditions, is solved by adopting Galerkin method. The influences of gravity, which is related to the mounting orientation of the pipe, longitudinal phase distribution profile, and flow velocity upon dynamics and stability of AFG-FCCPs are discussed in detail through generated numerical results. A special focus is also devoted to determination of critical flow velocity at which the instability occurs.