Smart materials and structures have attracted a significant amount of attention for their vibration control potential in engineering applications. Compared to the traditional active technique, shunt damping utilizes an external circuit across the terminals of smart structure based transducers to realize vibration control. Transducers can simultaneously serve as an actuator and a sensor. Such unique advantage offers a great potential for designing sensorless devices to be used in structural vibration control and reduction engineering. The present literature combines piezoelectric shunt damping (PSD) and electromagnetic shunt damping (EMSD), establishes a unified governing equation of PSD and EMSD, and reports the unique vibration control performance of these shunts. The schematic of shunt circuits is given and demonstrated, and some common control principles and equations of these shunts are summarized. Finally, challenges and perspective of the shunt damping technology are discussed, and suggestions made based on the knowledge and experience of the authors.

The compressed-spring structure is a simple and reliable mechanism to achieve negative stiffness, which has been vastly investigated for achieving quasi-zero-stiffness isolation. However, six-degrees-of-freedom quasi-zero-stiffness isolators based on this kind of negative-stiffness mechanism still have not been touched. In this study, we propose a six-degrees-of-freedom quasi-zero-stiffness isolation platform constructed by six modules that use compressed-spring structures. Its underlying quasi-zero-stiffness principles in the translational and torsional directions are explained. By establishing the static model of the platform and linearizing it at the static equilibrium position, we find that the linear cross-coupling effects appear if the static load exists. Linearized dynamic analysis of the isolation platform is then performed and the results demonstrate that by applying spring compression, the isolation frequency band can be expanded to lower frequency range in six directions. Because of cross-coupling effects resulted from the static load, the platform cannot achieve whole-frequency-range isolation in the coupling directions even if the spring compressions satisfy quasi-zero-stiffness conditions.

A bilateral piezoelectric stack actuator (BPSA) is introduced, and its actuated property is also analyzed. Usually, a piezoelectric stack can only undertake significant compressive loads but cannot tolerate tension, while this new actuator is able to

To suppress resonance and broaden the bandwidth for vibration absorption, a nonlinear dynamic vibration absorber (NDVA) with negative stiffness is developed in this paper. The magnetic negative stiffness spring (MNSS), the generation mechanism of negative stiffness, is composed of three magnet rings arranged in attraction, and employed to connect with mechanical spring in parallel. The magnetic force and its corresponding stiffness of the MNSS are investigated firstly. Attaching the NDVA to main mass, the dynamic equations of the coupled system is established, and the averaging method is also applied to the dynamic responses. With the aim of excellent vibration absorption performance of the NDVA, an iterative algorithm is proposed to perform the parameter optimization with the purpose of avoiding time consumption. Finally, the results show that the optimization algorithm can significantly improve the efficiency of parameter selection for the NDVA, resulting in the remarkable vibration attenuation for primary system and a larger bandwidth for vibration absorption.

This paper deals with the vibration control of a cantilever honeycomb sandwich plate by using Macro-Fiber Composite (MFC) piezoelectric actuator. Firstly, the honeycomb plate is equivalent to an orthogonal anisotropic plate. Secondly driving force and bending moment formulas of MFC actuator are derived based on the constitutive relations of the piezoelectric material, the equivalent parameters and bend deformation theory. The result reveals that driving force and bending moment not only depend on the driving voltage and piezoelectric strain constants (d33), but also have relationship with the elastic modulus of honeycomb plate. To simulate the vibration of cantilever honeycomb plate structure, the governing equation of the plate bonded with MFC actuators is derived. Finally, the vibration by proportional derivative (PD) control of system with MFC actuator is simulated. The results show that better control performance is obtained by using MFC actuator when system under impulse excitation and steady state sine excitation. The vibration amplitude is diminished over 75% under PD control.