Mathematical and computer finite element model in the ACELAN package of resonant impact on a spike was developed and a full-scale experiment was carried out. Two installations are considered, one based on a cantilever, the free end of which acts on the spike, and the second is a semi-passive round bimorph. Excitation of vibrations is carried out using an actuator based on piezoceramic elements. In the first installation, low-frequency vibrations of the stem with a spike are excited and the resonance frequency is determined at which only an spike with grain performs intense vibrations. The second installation is designed to excite high-frequency vibrations at which resonant movements of the grains themselves arise. The purpose of both installations is to separate the grain from the spike using resonance phenomena.

This paper addresses investigation of guided-wave excitation by angle-beam wedge piezoelectric (PZT) transducers in multilayered composite plate structure with orthotropic symmetry of the material. The aim of the present study is to determine the capability of such actuators to provide the controlled generation of an acoustic wave of a desirable type with the necessary wavelength, propagation distance and directivity. The studied CFRP (Carbon Fiber Reinforced Plastic) panel is considered to be homogenous, with effective elastic moduli and anisotropic structural damping, whose parameters were determined experimentally. According to the results of dispersion analysis and taking into account the data of wave attenuation in a highly damping CFRP composite, the two types of propagating waves A0 and S0 were considered theoretically and experimentally in the frequency range of 10–100 kHz. Using the results of a previous study, we reconstructed the structure of the wedge actuator, to develop its finite-element (FE) model, and a modal analysis was carried out that revealed the most intense natural vibration modes and their eigenfrequencies within the frequency range used. Both experimental and numerical studies of the generation, propagation, directivity and attenuation of waves in the orthotropic composite panel under study revealed the influence of the angular orientation of the actuator on the formation of wave patterns and allowed to determine the capabilities of the wave’s directivity control.

Based on the variational principle, equations and boundary conditions for transverse steady vibrations of a bimorph consisting of a piezoelectric and piezomagnetic layers are obtained. The results of calculations of natural frequencies are compared with the finite element model of the device in ACELAN.

This paper presents the application of the Pareto-based multicriteria optimization technique to problems of increasing the efficiency of piezoelectric generators (PEGs). The optimization problem was solved for two types of generators: cantilever and stack. For the cantilever generator, the task was to optimize the design in such a way as to obtain the maximum output power for a given mechanical excitation. The optimization process was divided into several stages, which significantly reduced the amount of calculations. The task of optimizing the stack type for a given form of mechanical loading consisted in finding the geometric parameters of the generator at which the output voltage and power would be maximum. In the result of solving both problems, sets of geometric design parameters of PEGs were obtained, on the basis of which efficient transducers can be developed for specific operating conditions. It turned out that this technique is more suitable for optimizing the design of cantilever generators than for stack ones in given constraints. The solution of both problems was realized using the finite element method.