The numerical modeling results of the full-scale experiment with low-frequency pulse excitation of the stack-type piezoelectric generator (PEG) for the energy storage device are described. PEG is a multilayer axisymmetric piezoceramic package. The dependence of the output voltage on the active load rate under the harmonic and non-stationary mechanical action of the PEG is studied. A finite element device model is developed in ANSYS , and a simplified one-dimensional analytical model is analyzed. The experimental results-to-numerical calculation correlation has shown their good convergence which allows using the analyzed numerical models to optimize the PEG design at the given external action frequency and active resistance value of the external electric circuit. In addition, it is found that the frequency dependence of the output voltage of the axial-type PEG is of a complex nature depending both on the compressive pulse loading level and the piezoelectric modulus value of the PEG sensitive element, and on the electrical load resistance.

The work objective is to determine the conditions for improving the operating efficiency of the balancing equipment. The problem is to increase accuracy and to reduce labor intensity of the rotor balancing. A rotor model on the balancing machine considered according to the vibration theory as a dynamic system with two degrees of freedom forms the basis of the research. As a result of the investigations, first, the necessity of applying vector influence coefficient values of the rotor model unbalance in each of the correction planes on the vibrations of the rotor poles on the balancer is proved. Secondly, the technique of their experimental determination is presented. The results obtained can be used to create balancing equipment (balancing machines and balancing sets) of new generation. The study is the development of the modern theory and practice balancing aimed at improving the adequacy of the dynamic rotor model.

The present work objective is searching for such forms of the cardboard corrugation which could effectively absorb the impact load on a cardboard sheet, both vertical and horizontal. The research subject is the depreciation efficiency of the cardboard package with a cell and an alternative (with MS-profile) structure by the action of shock across and along the honeycomb. Measurement and comparation of the deformation rate, as well as the shock absorption capacity of the sample cartons with the standard and alternative MS-corrugation are considered as the investigation tasks. The samples were under the impact force. Shock absorbing properties of the multilayer cardboard packaging in size of 127 × 127 mm were evaluated under the following conditions: drop height, 610 mm; impact speed, 3.5 m/s; falling weight, 12.5 kg; pressure load, 340 kg. In this case, pressing force, impact energy, deformation value is recorded. As a result of the experiments, it was found that a three- and five-layer sample with MS-profile has better shock absorbing properties (as compared to a standard cellular cardboard of the same thickness). The application of seven- and nine-layer cardboard with MS-profile is inappropriate due to a minor advantage over a three- and five-layer sample.

A problem on critical loads of the compressed rectangular plate containing continuously distributed sources of inherent stress is considered. The task analysis is based on the modification of the Karman nonlinear equations system for large deflections of elastic plates with dislocations and disclinations under different boundary conditions. By the introduction of a replacement for the stress function, the problem reduces to the treatment of two tasks: a linear boundary value problem concerning the stress function caused by internal sources and a system of nonlinear equations concerning the deflection and the stress function caused by external compressive loads, which possesses a trivial solution. The classical critical load is defined as the smallest eigenvalue of the linear boundary value problem obtained by the linearization of the nonlinear equations system relative to the trivial solution. Four types of boundary conditions are treated: all edges are variably restrained; all edges are simply supported; two opposite edges are stress-free, and the other two are either variably restrained or simply supported. Uniformly distributed compressive loads are equal on the opposite edges. It is established that if the measure of inconsistency is odd on one variable and odd or even on another variable, then the stresses caused only by internal sources, do not lead to the loss of the flat equilibrium state and do not affect the critical values of compressive loads.

Stability problems of the stationary trajectories of the tool elastic deformational displacement under the longitudinal endmilling are considered. In the moving coordinates which displacement is determined by the actuators motion, the stationary steady state is not an equilibrium point (as when turning), but some closed trajectory. The synergetic concept of the analysis of trajectories executed in two stages is used. At the first stage, the established stationary trajectories are calculated according to the offered technique. At the second stage, the stability of these trajectories is analyzed. A case, when the equation parameters in variations under the fixed trajectory can be considered constant within the system impulsive reaction, is considered. Features of the stationary trajectories formation are studied; conditions under which they converge to some steady trajectories are obtained. Besides, some general properties of the loss of balance are received. An example of analysis is cited, and recommendations for ensuring stability of a trajectory of the established form-building motions are given.

The main work objective is the creation of the scientific background for correct determination of a set of requirements to the fabrication material with a high-wearing feature under the droplet impingement erosion. A review of a backward and present state of the art of the national and foreign investigations in the field of the droplet impingement erosion of metal materials is carried out. The main outcome is as follows: insufficient fundamentality of research in this area; limitation of the used theoretical models; one-sided approach of many authors to the phenomenon that combines a whole set of factors of different physical nature. On this background, the author's concept of the erosive wear process of metal under the influence of two-phase mist flow is presented. Particular attention is paid to a new scientific hypothesis of the active hydrogen effect on the fracture of metal under the hypervelocity dropwise collisions.

The concept of e-Mind Machine, a system that monitors the status of multioperational machines, is considered. The existing international and domestic monitoring systems, as well as the essential aspects of monitoring specifying e-Mind Machine features are analyzed. The structure of the e-Mind Machine module organization is presented. The need for converting test data into a knowledge system when the perspective monitoring systems operate at the multioperational machines is justified. Benefits of the forecasting methods application are determined. New concepts such as fuzzy boundary of operability/reliability and fuzzy boundary of parametric uptime are introduced. It is shown that the use of the intelligent control opens up fresh opportunities for the monitoring automation. The application of the e-Mind Machine module as an onboard intelligent system maximizes the part-processing efficiency and reliability in combination with the machine self-service.

The work objective is to study electrodynamic processes in the frequency-controlled drive (FCD) by the mathematical modeling method, in particular, in the two-current mode of the dynamic braking considering the 5th and 7th current harmonics of the induction motor (IM) stator. The features of forming IM stator current low frequencies (0.2-15 Hz) by the autonomous voltage inverter (AVI) followed by the additional electricity loss in the FCD, and the appearance of torque ripple on the IM shaft causing jerkiness of the actuating mechanism (AM) of the production machine (PM) executive device (ED) in the low speed zone and complicating their locating in the prearranged position, are given. It is hard to implement the FCD scheduled deceleration without trajectory correction at the friction forces ambiguity in the ED AM mobility links and availability of the torque ripple on the IM shaft. To solve this problem, the authors offer, first, to use a spatial-vector pulse-width modulation (SV PWM) with m-fold submodulation of the carrier frequency (CF) and without submodulation in the IM braking mode. Secondly, it is reasonable to apply (momentarily in a low speed area) the principle of linearization by oscillation to reduce the K friction coefficient to a decreased value in the ED AM mobility links by the IM rotor microvibration due to the 5th and 7th harmonics of the stator current. Thus, the work on modeling FCD (in Matlab + Simulink software package) allows more accurately define the impact of the 5th and 7th harmonics of the IM stator current on the capability of the software implementation of the two-current mode of the FCD dynamic braking while reducing the total energy loss in the ED AM low-speed motion area. In addition, the applicability of the proposed solutions of the electric drives of mechatronic and robotic multipurpose systems with higher requirements for positioning in the basic AM - AVI circuits is confirmed.

The formation of complexes of nitrogenated molecules with a small copper cluster Cu_n (n=1-7, 13) is systematically studied through the calculations by the density functional theory method. It is shown that the molecules of R₁N=Y (Y=CR₂R₃, NR₂, O) are promising for searching agents for copper clusters, as they are synthetically-available, can exert reducing properties, are firmly bound to the copper atoms, and do not distort the original cluster structure. Using any bulky substituent R, it is possible to block access to a large surface area of the cluster for aggressive compounds. Oxygen complexes on the surface of the copper cluster drastically fall short of the strength of the structures formed by molecules R₁N=Y (Y=CR₂R₃, NR₂, O). Depending on the cluster size, the interaction force varies in a sinusoidal manner from minimum to maximum.

The work goal is to study the human factor role in a safety problem of the ultrasonic testing of high-duty welded objects. The key objective and subjective factors determining the human reliability of the man-machine systems are analyzed. It is shown that subjective factors are divided into three main subgroups: the level of training, individual characteristics and functional state of the human-operator. On the basis of the job specification approach, the most important skills of the ultrasonic testing (UST) operators are determined, and the original training facilities for their purposeful development are worked out. Some modifications of the computerized simulator-examiner for training and the integrated proficiency assessment of the UST operators of the joint welds are developed. Based on the conducted analysis of the individual peculiarities of the personality, it is found that the medicobiologic structure of a person plays a crucial role and determines some basic professionally important qualities for the UST operator occupation. The influence of the functional state of the ultrasonic testing operators on the results of the professional activities is investigated by experiment.

The work objective is to study the fundamental processes of forming hot-worked powder steels (HWPS) and bonding the particulate material on the existing and newly formed contact surfaces. The role of splicing is particularly great in the process of manufacturing materials under the strained conditions. Evidently, whatever the structure in the amount of the material surrounded by the former powder particle surface, the powder material properties will be determined not by the morphological structural features, but by the splice quality up to a defined level of splicing. Therefore, the study of interparticle splicing in the formation of HWPS is a crucial task of the materials technology. Thus, further processing of hot pressurized powder steels can be offered not only for forming, but to improve their mechanical properties as well.

The work objective is to study the impact of the drill design value and geometrics on the quality of the processed holes, the efficiency, and the machining dynamics of the high-strength polymer composite - fiberglass plastic reinforced by titanium foil. Packs of the reinforcing layers made from the titanium foil or carbon fiber tapes are often used in the highly-loaded polymer composite structures. Processing in several operations and the application of sharp-ground tools provide the required dimensional accuracy, the surface macro- and microgeometry of the hole, and allow avoiding the delamination. The process of drilling fiberglass laminates under different patterns of HSS drills sharpening is studied. The data obtained allow determining the optimum type of instrument and operation mode taking into account the dependence of the high-altitude roughness parameters, the nature and amount of delamination in the entry (exit point) of the drill. The vibroactivity of the drilling process and its relationship with the quality metrics are studied using the computer-aided torque-sensing system. Some proposals for improving the hole-making technology applying to the glass-fiber spars of the main and tail helicopter rotors are developed.

Wheelsets directly subjected to a force impact under the interaction of wheels and rails are intense noisemakers when moving, including overhead cranes and railway rolling stock. Despite the design and functional differences, the calculation of vibroacoustic characteristics can be made from the unified positions. It should be noted that the calculation accuracy of the sound pressure levels and vibrations is in large part determined by the precision of setting the frequency-dependent loss factors of the vibration energy. Theoretical studies of this physical and mechanical value are rather complicated. Therefore, the regression curves obtained on the basis of the mathematical treatment of the experimental coefficient values of the wheelset assembly losses and the approximation dependencies by the exponential polynomials of various degrees should be used for the engineering analysis of the sound pressure levels and vibrations.

The inductor which allows the usage of the magnetic field in the agriculture technological processes is considered. The measuring technique of the electromagnetic field vector characterization - magnetic induction that evaluates the quality of the technological process in the inductor chamber - is offered. Intensity, directivity, and uniformity of the magnetic field in the inductor working chamber are investigated. The techniques of the instrumental, direct and indirect measurements, and statistical data processing, as well as methods of analog-to-digital data conversion are used. A cybernetic model of the experimental research to assess the inductor performance quality is developed. The distribution of the radial and axial components of the magnetic induction in the working chamber is determined; the area with the most uniform magnitude and the magnetic-field direction which forms the inductor working area is identified. The most significant component of the magnetic induction vector for this process and the type of inductor is revealed. The results obtained are important for the development of new inductor constructions.

The work objective is to improve the automation efficiency of the technological processes of the chemical industry and the related industries. A typical for the industry solution preparation process is considered; and the task of developing a vector control law, effective in terms of both intensity or speed and cross-invariance of the management processes of various technological variables, is solved. To cope with this task, the approach to the control laws synthesis based on the desired characteristics of the synthesized control system is taken. A mathematical model of the quasi-optimal speed control is used to construct the desired mathematical model of the controlled machine for the solution preparation. The synthesis is resulted in a rather complex non-linear vector control law which, however, provides all the properties inherent in the paradigm of its creation and implementation. Simulation modeling of a multistage automatic control system with the implementation of the synthesized laws is carried out, as well as the research of the constructed model. This allows fully confirm an absolute control autonomy of the outflow solution level in the unit and of its concentration. Besides, the independence of the controlled variables from the changing load - flow fluid preparation - is established. The results obtained are intended for the implementation in the chemical technology and the related industries (food processing, oil refining, etc.). The materials and the research results presented show that for an effective synthesis of the vector control laws of nonlinear multiply connected objects, the method of reference mathematical models can be applied along with the quasi-optimization speed performance of these laws.

A mathematical model of the feed mixing in a tilted single-screw circulating batch mixer is presented. The model includes a system of equations of control component concentration change in the representative zones of the mixer. The feed material state at the mixer loading start-up and hulling onset is considered for solving a system of equations. A flow pattern and mathematical expressions of the forces affecting the feed during the charging process are given. As a consequence of the equations solution, the dependence for determining the height of the feed layer on the mixer hopper geometrics and the physical and mechanical-and physical properties of the feed material is obtained. A flow pattern of the forces affecting the feed material at the hulling onset is shown. The layer height value of the hulled material is determined with account of the dependence obtained for the first state of feed. It is determined that two zones are formed from the area of the original conditional displacement. The first one is a plug-flow zone of the bottom-up feed transportation, and the second one is a plug-flow zone in the direction of the downward feed hulling. The cross-sectional area of these zones can be determined on the basis of the derived equations.

The work objective is to study the metrological aspects of the acoustic emission (AE) method as applied to the monitoring of the hydrogen peroxide decay rate. The AE changing parameter that determines the method metrological properties as a whole is selected. It is established that the process of the hydrogen peroxide decomposition causes stress waves in the local liquid volume. This leads to the formation of the acoustic signals that allow firmly control this process through the AE method. The metrological evaluation of the method implemented in two stages is analyzed. The significance of the first stage allowing for the quality relative AE-research is identified. The experiments performed have confirmed high sensitivity of the proposed method. Thus, it is possible to carry out effective relative studies of the compared processes according to the AE parameters. The acoustic emission data show that instrumental and methodological errors of the AE method in general can be significant in case of the counter conditions, and this fact can be a benchmark for future research.