Layerwise partial mixed finite element analysis of magneto-electro-elastic plates

One of the most frequent applications of magnetostrictive actuator technology is the active structural vibration control (AVC). Magnetostrictive actuators (MAs) can deliver high-output forces and can be driven at high frequencies. These characteristics make them suitable for a variety of vibration control applications. The use of this technology, however, requires an accurate knowledge of the dynamics of such actuators. Several models are available in the literature. However, their use in control applications, characterized by high dynamics, is often limited by nonlinearities and complexity of the model. To overcome this difficulty, the paper introduces a linear model of magnetostrictive actuators that is valid in a range of frequencies below 2 kHz. The assumptions supporting the linearity of the system are discussed and the theoretical model is presented. Finally the model is validated through experimental tests carried out on two different magnetostrictive actuators.

A model of magnetostrictive actuators for active vibration control

In this paper, the active vibration control of conical shells is studied using velocity feedback and linear quadratic regulator methods. Up to now, many researches on the active vibration control o...

Active vibration control of conical shells using piezoelectric materials

This paper presents a simulation of vibration suppression of a laminated composite beam embedded with actuators of a giant magnetostrictive material subjected to control magnetic fields. It has been found that the strains generated in the material are not only significantly larger than ones created by many other smart materials but also exhibit some inherent nonlinearities. To utilize the full potential of these materials in active vibration control, these nonlinearities should be characterized in the control system as accurately as possible. In this simulation of nonlinear dynamic controls, the control law with negative velocity feedback and the analytical nonlinear constitutive model of the magnetostrictive layer are employed. The numerical results show that this proposed approach is efficient not only in a linear zone but also in nonlinear zones (dead zone and saturation zone) of magnetostrictive curves in vibration suppression. Compared with those from the control system based on the linear constitutive relations of the material, it is found that the simulation results based on the linear model are efficient only when the magnetostrictive relations are located in the linear zone. Once the system has some departure from the linear zone, however, the results from the linear model become unacceptable. Finally, the effect of material properties, lamination schemes and location of the magnetostrictive layers on vibration suppression of the practical system is evaluated.

Vibration suppression of laminated composite beams using actuators of giant magnetostrictive materials

Vibration suppression of cantilever laminated composite plate with nonlinear giant magnetostrictive material layers

Active control of beam with magnetostrictive layer

This paper deals with the damping characteristics obtained by using a distributed magnetostrictive layer, bonded to an aluminum plate for different boundary conditions and coil configurations. The magnetostrictive layer is used to induce the actuating force to control vibration in the plate, based on a negative velocity feedback control law. The control input is the current to the solenoid surrounding the plate. In several prior formulations in the literature, it has been assumed that the current through the coil is a function of axial distance. Even though this assumption is mathematically valid, a physical consideration of the problem does not allow such an assumption. In the present study, perhaps for the first time, a finite element formulation, physically consistent with the problem, has been developed. Vibration reduction in the plate by positioning the magnetostrictive layer and its current carrying actuating coil pair along the plate is investigated. Issues associated with control for different boundary condition are highlighted.

J.S. Kumar

Papers

Active control of beam with magnetostrictive layer

Active control of simply supported plates with a magnetostrictive layer

Active control of cylindrical shell with magnetostrictive layer