In this paper, optimal active vibration control of a micro sandwich beam is studied. Face sheets are made from piezoelectric materials and reinforced by functionally graded distributions of carbon nanotubes. Also bottom and top face sheets operate as distributed sensor and actuator, respectively. Based on modified strain gradient theory and Hamilton's principle , the governing equations of motion for presented smart micro Reddy beam are derived and optimal active vibration control is applied using state-space form of equations of motion and linear quadratic regulator algorithm. The results show that considering MSGT, the amplitude of the center point deflection and settling time decrease. Also CNTs distributions effect on stability and active vibration control of the smart structure and LQR algorithm is essentially an automated way of finding an appropriate state-feedback controller. This study is a theoretical background for more research and further experimental investigation, in the field of micro smart structures.

Active control of micro Reddy beam integrated with functionally graded nanocomposite sensor and actuator based on linear quadratic regulator method

Abstract A non-linear analysis of a delaminated curved sandwich panel with a compliant core, and a delamination (debond) at one of the face–core interfaces, and subjected to a thermal field and a mechanical loading or combined is presented. The mathematical formulation outlines the governing equations along with the stress and displacements fields for the cases where the core properties are either temperature independent ( TI ) or temperature dependent ( TD ). A variational formulation is used following the principles of the high-order sandwich panel theory (HSAPT) to derive the field equations along with the appropriate continuity conditions. The non-linear analysis includes geometrical non-linearities in the face sheets caused by rotation of the face cross sections, and high-order effects that are the result of the radially (transversely) flexible (or compliant) core. The core stress and displacements fields with temperature-dependent ( TD ) mechanical properties are determined in closed form using an equivalent polynomial description of the varying properties. The numerical study describes the non-linear response of delaminated curved sandwich panels subjected to mechanical concentrated loads, thermally induced deformations and simultaneous thermal and mechanical loads. In the combined loading case the mechanical loads are below the limit point load level of the mechanical response, and the imposed temperature field is varied. The results are displayed in terms of plots of various structural quantities along the sandwich panel length (circumference), equilibrium curves and strain energy release rate curves. It is shown that the combined thermo-mechanical response shifts the linear or non-linear responses,observed for the separate cases of either temperature induced deformations or mechanical loading, into a strongly non-linear response with limit point behaviour and large stresses in vicinity of supports, loads and tips of delaminated zone.

Non-Linear Thermo-mechanical Behaviour of Delaminated Curved Sandwich Panels with a Compliant Core

Magneto-electro-elastic semi-analytical models for free vibration and transient dynamic responses of composite cylindrical shell structures

Investigation of the time elapsed effect on residual stress measurement in a composite plate by DIC method

In this paper, the nonlinear vibration control of sandwich shallow doubly-curved nanoshells with functionally graded piezoelectric (FGP) nanocomposite sensors and actuators is investigated based on

An analytical solution for nonlinear vibration control of sandwich shallow doubly-curved nanoshells with functionally graded piezoelectric nanocomposite sensors and actuators

In this article, based on high-order sandwich panel theory and modified strain gradient theory, free vibration analysis of a micro-magneto-electro-elastic sandwich panel with a transversely flexible core and functionally graded carbon nanotube–reinforced nanocomposite face sheets is investigated. Also, the influences of temperature-dependent material properties and various circuit boundary conditions such as open and closed are considered in this study. Carbon nanotubes are arranged in longitudinal direction inside polyvinylidene fluoride matrix with various functionally graded (FG) distributions such as uniform, FG-V, FG-A, FG-X, and FG-O in the face sheets. The generalized rule of mixture is employed to predict mechanical, electrical, magnetic, and thermal properties of micro-sandwich composite panel. The classical shell theory and an elasticity high-order theory are used for the face sheets and the core, respectively. Then, the governing equations of motion are derived using Hamilton’s principle. In th...

Free vibration analysis of micro-magneto-electro-elastic cylindrical sandwich panel considering functionally graded carbon nanotube–reinforced nanocomposite face sheets, various circuit boundary conditions, and temperature-dependent material properties using high-order sandwich panel theory and modified strain gradient theory:

SH Edjtahed

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