# مقالههای m.r eslami

**توجه:**محتویات این صفحه به صورت خودکار پردازش شده و مقالههای نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده میشوند.

##### ۱Analytical and finite element solutions for bending of functionally graded piezoelectric beams

اطلاعات انتشار:
هفدهمین کنفرانس سالانه مهندسی مکانیک،
سال ۱۳۸۸

تعداد صفحات:
۶

This paper makes attempt to investigate bending of functionally graded piezoelectric beams based on the euler –bernoulli beam theory under mechanical load.<\div>

##### ۲Coupled Thermoelasticity of Functionally Graded Plates Based on First–Order Shear Deformation Theory

اطلاعات انتشار:
هجدهمین کنفرانس سالانه مهندسی مکانیک،
سال ۱۳۸۹

تعداد صفحات:
۱۰

In this study, an analytical solution is presented for a plate based on the first–order shear deformation theory with functionally graded materials (FGM) subjected to lateral thermal shock loads. Material properties of the plate, except Poisson’s ratio, are assumed to be graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents. The solution is obtained under classical coupled thermoelastic assumption. A third–order polynomial temperature profile has been considered across the plate thickness with unknown constants. By substituting the profile into equations of motion and energy equation and applying Galerkin method we acquire nine equations for analyzing coupled thermoelasticity of the FGM plate which must be solved simultaneously. The governing partial differential equations are solved using Fourier series expansion method. Using the Laplace transform, the unknown variables are obtained in the Laplace domain. Applying the analytical Laplace inversion method, the solution in time domain is derived. The analytical approach supports us to be able to submit a mathematical expression for classical coupled thermoelastity of the FGM plate. Computed results for the plate with simply supported boundary conditions are presented for different power law indices and various aspect ratios of the plate. Results show that the plate under coupledthermoelasticity assumption vibrates around the steady state situation and vibration amplitude decreases intensively with passing the time. Although, coupled thermoelasticity assumption affects both of temperature and deflection responses, the coupling effect is more apparent in the lateral deflection of the plate. Furthermore validating the process is accomplished by verifying thermomechanical responses and natural frequencies of the FGM plate based on the FSDT with known data reported in the literature.<\div>

##### ۳Buckling of Piezoelectric Functionally Graded Material Beams

اطلاعات انتشار:
دومین کنفرانس بین المللی کامپوزیت،
سال ۱۳۸۹

تعداد صفحات:
۶

Buckling analysis of functionally graded material (FGM) beams with surface–bonded piezoelectric layers which are subjected to both mechanical axial loading and constant voltage is studied in this paper. The material non–homogeneous properties of FGM beam are assumed to vary smoothly by distribution of power law through the beam thickness. It is assumed that the applied voltage to the piezoelectric layers is in the thickness direction and the electric field is generated in the thickness direction, too. The Euler–Bernoulli beam theory and nonlinear strain–displacement relation are used to obtain the equilibrium equations of the piezoelectric FGM beam. These equations may be useful for the static analysis of piezoelectric FGM beams. Based on the adjacent criterion, the stability equations for a perfect piezoelectric FGM beam are derived and by the pre–buckling analysis of the beam, buckling force is derived. Six types of boundary conditions with possible combination of simply–supported, clamped, free, and the roller edges are assumed for the beam and closed–form solutions are presented to evaluate the critical buckling load. The effects of the applied actuator voltage, beam geometry, boundary conditions, and power law index of functionally graded material on the buckling load are investigated<\div>

##### ۴Elastic buckling of FGM cylindrical shell surrounded by an elastic foundation

اطلاعات انتشار:
دومین کنفرانس بین المللی کامپوزیت،
سال ۱۳۸۹

تعداد صفحات:
۶

This research inspects the elastic buckling of FGM cylindrical shell, resting on two–parameters elastic foundation, subjected to external pressure load. Material properties of functionally graded cylindrical shell are graded in the thickness direction according to a power law direction. Theoretical formulations are derived based on the classical shell theory. The effects of shell geometry, volume fraction exponent, and foundation parameters on critical buckling load of FGM cylindrical shells are investigated. It is inferred from the results that the elastic foundation postpones the critical buckling load and swifts mode shapes of elastic buckling.<\div>

##### ۵Free Vibration Analysis of a Functionally Graded Piezoelectric Beam Based on Higher–order Beam Theory Using the Finite Fourier Transformation Method

اطلاعات انتشار:
دومین کنفرانس بین المللی کامپوزیت،
سال ۱۳۸۹

تعداد صفحات:
۷

This paper presents the free vibration characteristics of a laminated functionally graded piezoelectric material (FGPM) beam using the higher–order shear deformation beam theory. The beam consists of three layers; the top and bottom homogeneous layers are divided by a non–homogeneous FGPM transit interlayer. The material properties of the FGPM interlayer are assumed to vary through the thickness direction following a power law distribution. The beam is simply supported and grounded in its two ends. The governing equations are derived using Hamilton's principle. The resulting system of differential equations of vibration is solved using the analytical hybrid Fourier method. Initially, the convergence of the present solution is examined and the obtained results are compared with previous studies and Finite Element Method (FEM). The effects of parameters, such as the material composition, beam's geometry and shear deformation on natural frequencies are investigated. In addition, by changing the thickness of the FGPM interlayer the present model is compared with the traditional bimorph actuators.<\div>

##### ۶Thermal buckling of functionally graded truncated conical shells

اطلاعات انتشار:
بیستمین کنفرانس سالانه مهندسی مکانیک،
سال ۱۳۹۱

تعداد صفحات:
۴

In this paper, linear thermal buckling of a thin functionally graded material (FGM) truncated conical shell subjected to the uniform temperature rise loading is presented. Material properties of the FGM shell are assumed to vary continuously through the thickness direction. Equilibrium and stability equations are obtained based on the variational approach considering the first order shell theory and Sander's nonlinear kinematics equations. Galerkin method is adopted to obtain the critical buckling temperature difference of the conical shell. The results are compared with the known data in the literature. Upon the numerical results, effects of various parameters such as semi–vertex angel and FG parameter of material distribution are investigated on thermal instability of the conical shell.<\div>

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