Yongfei Zhang

Bio: Yongfei Zhang is an academic researcher from Lanzhou University. The author has contributed to research in topics: Hysteresis & Newmark-beta method. The author has an hindex of 1, co-authored 2 publications receiving 28 citations.

Vibration suppression of cantilevered piezoelectric laminated composite rectangular plate subjected to aerodynamic force in hygrothermal environment

Abstract: In this paper, a robust control method is proposed for the vibration suppression of the piezoelectric laminated composite cantilever rectangular plate subjected to the aerodynamic force in the hygrothermal environment. The laminated composite cantilever rectangular plate is placed on the piezoelectric actuator and sensor for the upper and lower surfaces. The classical laminated composite plate theory and Hamilton's principle are applied to derive the dynamic equation of motion for the piezoelectric laminated composite cantilever rectangular plate under the aerodynamic force and hygrothermal loads. The structural damping is considered for the piezoelectric laminated composite cantilever rectangular plate. Galerkin method is used to obtain a two-degree-of-freedom discrete ordinary differential control equation of motion. For the active vibration suppression, a robust controller for the uncertain systems is designed through the obtained ordinary differential equation of motion. Moreover, the full-dimensional state observer is constructed to calculate the close-loop system. The influences of the moisture, temperature and geometric parameters on the dynamics behaviors of the piezoelectric laminated composite cantilever rectangular plate are investigated. The accuracy and effectiveness of the robust controller are verified in terms of the moisture concentration, temperature, aspect ratio, damping and parameter uncertainty by numerical simulations.

Hygrothermal effect on vibration of magnetostrictive viscoelastic sandwich plates supported by Pasternak's foundations

Abstract: In hygrothermal environment, vibration study of a simply supported smart sandwich plate embedded in an elastic substrate medium is presented in the present article. The sandwich plate contains layers of fiber-reinforced and magnetostrictive materials and core of viscoelastic material. The kinematic equations system is derived via employing Hamilton's principle with considering the transverse shear strains with and without the normal strains effect. Various numerical examples are carried out to study the effects of temperature rise, degree of moisture concentration, elastic foundations parameters, thickness ratio, aspect ratio, thickness ratio of magnetostrictive layer to viscoelastic layer, modes, lamination schemes, magnitude of the feedback coefficient, position of the magnetostrictive layers and viscoelastic structural damping coefficient on controlled motion and vibration characteristics of plate. Some observation about influences of the temperature and humidity concentrations on vibration characteristics of studied plate are presented in detail. The outcomes indicate that the hygrothermal environments have negative effects on vibration suppression of advanced composite structures especially the uniform hygrothermal distribution. The frequencies increase with increasing the viscoelastic structural damping coefficient and the foundation constants.

Hygrothermal forced vibration of a viscoelastic laminated plate with magnetostrictive actuators resting on viscoelastic foundations

Abstract: The article presents a vibration analysis of a laminated composite sandwich plate containing viscoelastic layers in the core and faces of the plate. The sandwich plate includes magnetostrictive actuating layers, rests on a three-parameter viscoelastic medium, and undergoes to hygrothermal environmental conditions and in-plane forces in $$x$$ and $$y$$ directions. The viscoelastic layers are considered as Kelvin–Voigt viscoelastic model. The partial differential equations system is deduced according to the dynamic version of the principle of virtual displacements and is based on a theory that accounts for the exponential distribution of transverse shear deformation. The analytical Navier’s solution type is obtained to investigate the parametric effect of the location of smart layers, lamination schemes, modes, the feedback gain control value, viscoelastic structural damping, thickness ratio, the aspect ratio, viscoelastic layer thickness-to-magnetostrictive layer thickness ratio, foundation, in-plane forces, temperature and moisture on vibration characteristics of the sandwich plate. The outcomes show that the deformation and vibration in the structure can be controlled by changing the smart layer position and value of the feedback gain control parameter as well as the studied system stability can be affected by the value of viscoelastic structural damping and foundation constants. Besides, the absorption of moisture in matrix material increases the deflection of structure and increases the damping time. The results of this study can contribute to the development of the design of smart structural applications, especially those that require foundations to support them and deal with their dynamic response as well as provide a reference framework for studies of the impacts of humid environments on such structures in the presence of in-plane forces, especially, in the applications subjected to various forces and environmental conditions. Many of these systems require foundations to support the structures and deal with their dynamic response such as civil and mechanical structural applications and the aerospace and aeronautical vehicles.

Vibration suppression of magnetostrictive laminated beams resting on viscoelastic foundation

Abstract: The vibration suppression analysis of a simply-supported laminated composite beam with magnetostrictive layers resting on visco-Pasternak’s foundation is presented. The constant gain distributed controller of the velocity feedback is utilized for the purpose of vibration damping. The formulation of displacement field is proposed according to Euler-Bernoulli’s classical beam theory (ECBT), Timoshenko’s first-order beam theory (TFBT), Reddy’s third-order shear deformation beam theory, and the simple sinusoidal shear deformation beam theory. Hamilton’s principle is utilized to give the equations of motion and then to describe the vibration of the current beam. Based on Navier’s approach, the solution of the dynamic system is obtained. The effects of the material properties, the modes, the thickness ratios, the lamination schemes, the magnitudes of the feedback coefficient, the position of magnetostrictive layers at the structure, and the foundation modules are extensively studied and discussed.

Vibration suppression of advanced plates embedded magnetostrictive layers via various theories

Abstract: Vibration suppression analysis of a laminated composite plate embedded magnetostrictive layers is presented with/without the transverse shear and normal strains effects are taken into account in this study. For purpose of vibration suppression, the velocity feedback control with constant gain distributed is applied. The formulation of problem is written to give five theories are Euler-Bernoulli’s classical plate theory, the Timoshenko’s first-order and Reddy’s third-order shear deformation plate theories, simple and refined sinusoidal shear deformation plate theories and other theories. The governing equations of motion are obtained using the Hamilton’s principle. Navier’s method is applied to discuss the solution of vibration problem at the simply-supported boundary conditions. Some effects are extensively studied and discussed such the impact of material properties, modes, thickness and number of the magnetostrictive layers, lamination schemes, magnitude of the feedback coefficient and location of the magnetostrictive layers on vibration suppression of the system. Numerical results are reported and illustrated, and various conclusions are formulated.