The current paper presents a thorough study on the pull-in instability of nanoelectromechanical rectangular plates under intermolecular, hydrostatic, and thermal actuations. Based on the Kirchhoff theory along with Er...The current paper presents a thorough study on the pull-in instability of nanoelectromechanical rectangular plates under intermolecular, hydrostatic, and thermal actuations. Based on the Kirchhoff theory along with Eringen's nonlocal elasticity theory, a nonclassical model is developed. Using the Galerkin method(GM), the governing equation which is a nonlinear partial differential equation(NLPDE) of the fourth order is converted to a nonlinear ordinary differential equation(NLODE) in the time domain. Then, the reduced NLODE is solved analytically by means of the homotopy analysis method. At the end, the effects of model parameters as well as the nonlocal parameter on the deflection, nonlinear frequency, and dynamic pull-in voltage are explored.展开更多
In this investigation,the analysis of the nonlinear vibroacoustic and sound transmission loss behaviors of plates made of functionally graded material is presented.It is assumed that the properties of the functionally...In this investigation,the analysis of the nonlinear vibroacoustic and sound transmission loss behaviors of plates made of functionally graded material is presented.It is assumed that the properties of the functionally graded plates are in the form of the simple power law scheme and continuous along the thickness,under thermal load and incident oblique plane sound wave as well as the first-order shear deformation theory.For this purpose,first,using Hamilton’s principle,the nonlinear partial differential equations of motion are derived by the displacement field function approach and by considering the nonlinear von K´arm´an strain-displacement relations.To solve the equations,using the Galerkin method,the nonlinear partial differential equations of motion lead to Duffing equation.Then,using the homotopy analysis method,the equation of the transverse movement of the plate is solved semi-analytically to obtain the nonlinear frequencies.Finally,the nonlinear vibration and acoustic response of functionally graded plates are studied by considering the variation of the important parameters such as aspect ratio,dimensionless amplitude,volume fraction power of functionally graded material,external acoustic pressure,incidence and azimuthal angles,temperature changes,phase portrait,sound transmission loss,velocity and average mean square velocity of drive point and sound power level of the functionally graded plate.Results show increasing the incidence angle leads increase in hardening effects and sound transmission loss,but growing the azimuthal angle does not have much effect on the frequency-response and sound transmission loss in the absence of the external mean flow.Also,increasing temperature changes lead to decrease in hardening effects and sound transmission loss.展开更多
文摘The current paper presents a thorough study on the pull-in instability of nanoelectromechanical rectangular plates under intermolecular, hydrostatic, and thermal actuations. Based on the Kirchhoff theory along with Eringen's nonlocal elasticity theory, a nonclassical model is developed. Using the Galerkin method(GM), the governing equation which is a nonlinear partial differential equation(NLPDE) of the fourth order is converted to a nonlinear ordinary differential equation(NLODE) in the time domain. Then, the reduced NLODE is solved analytically by means of the homotopy analysis method. At the end, the effects of model parameters as well as the nonlocal parameter on the deflection, nonlinear frequency, and dynamic pull-in voltage are explored.
文摘In this investigation,the analysis of the nonlinear vibroacoustic and sound transmission loss behaviors of plates made of functionally graded material is presented.It is assumed that the properties of the functionally graded plates are in the form of the simple power law scheme and continuous along the thickness,under thermal load and incident oblique plane sound wave as well as the first-order shear deformation theory.For this purpose,first,using Hamilton’s principle,the nonlinear partial differential equations of motion are derived by the displacement field function approach and by considering the nonlinear von K´arm´an strain-displacement relations.To solve the equations,using the Galerkin method,the nonlinear partial differential equations of motion lead to Duffing equation.Then,using the homotopy analysis method,the equation of the transverse movement of the plate is solved semi-analytically to obtain the nonlinear frequencies.Finally,the nonlinear vibration and acoustic response of functionally graded plates are studied by considering the variation of the important parameters such as aspect ratio,dimensionless amplitude,volume fraction power of functionally graded material,external acoustic pressure,incidence and azimuthal angles,temperature changes,phase portrait,sound transmission loss,velocity and average mean square velocity of drive point and sound power level of the functionally graded plate.Results show increasing the incidence angle leads increase in hardening effects and sound transmission loss,but growing the azimuthal angle does not have much effect on the frequency-response and sound transmission loss in the absence of the external mean flow.Also,increasing temperature changes lead to decrease in hardening effects and sound transmission loss.
