Experimental analysis of the oscillations of two-mass system with self-synchronizing unbalance vibration exciters

In this work the experimental researches of dynamics of a model of a chain-type two-mass oscillatory system with two unbalance vibration exciters are carried out. The method of smooth variation of the debalances speed is used to analyze the amplitude-frequency response of the model. The modes of synchronous rotation of debalances are studied depending on the control parameter – the frequency of the supply voltage. The power characteristics of the electric drive and the influence of the carrying body oscillations on the power consumed by the exciter are established. It is shown that the effect of adaptive self-synchronization of debalances occur in the mechanical system, when the oscillation modes of carrying body vary with the excitation frequency

An algorithm for automatic adjustment of the vibrational technological machine to the resonant regime

The problem of stabilization resonant oscillation of mechanical system excited by unbalanced rotor of an asynchronous AC motor is considered. An algorithm for automatic adjustment of the vibrational technological machine to the resonant regime at changing process loads and/or supply voltage is proposed

Adaptive properties of a self-synchronization effect of unbalanced vibroexciters

This paper describes the results of the experimental studies of vibrations of one-mass system on an elastic suspension with two unbalanced vibrators in a wide range of excitation frequencies. The technique of the tests and results analysis is given. The paper shows that in a mechanical system an effect of self-oscillating adaptive self-synchronization of unbalanced masses takes place when changing the vibration forms of the carrier body, depending on the excitation frequency

Simulation of control system for resonant vibrating machines with two unbalanced exciters

Problems related to design of high-performance vibrating machines are described in this paper. For this purpose, numerical simulation of flat solid body oscillations excited by two unbalanced exciters was carried out. The developed model takes into account AC motor characteristics. A control system for automatic resonant tuning under varying system parameters is developed

Residual stress and microhardness increasing induced by two-sided laser shock processing

Two-sided laser shock processing (TSLSP) is often employed to improve the surface quality of thin section components, which can reduce excessive plastic deformation induced by one-sided laser shock processing. Residual stresses (RS) field induced in a thin Ti-6Al-4V alloy plate by TSLSP was investigated through numerical simulation. The multiple TSLSP impacts and the increasing laser shock pressure were found to have significant effects on the RS field. Microhardness distribution on the section of specimen, calculated from RS by Carlsson-Larsson model, is analyze

Residual stresses distribution in Ti-6Al-4V titanium alloys during laser shock processing

Laser shock processing (LSP) of materials is an innovative material processing technology in which considerable compressive residual stresses are generated in the surface region and contribute to improved strength and performance parameters. We analyze performance capabilities of lasers operating at higher frequencies and lower energy levels compared to lasers used with traditional LSP technologies. Finite element modeling of compressive residual stresses at different stages of laser spot overlap for Ti-6Al-4V titanium alloys is carried out. The results are compared with the known experimental data. It is shown that they are correlate well with each other

Analysis of dynamic properties of two-mass system with inertial exciter of limited power

In this paper a forced oscillations of two-mass system, induced by unbalance vibration exciter driven by asynchronous AC motor of limited power, are considered. The mathematical model of the system is obtained by taking into account static characteristic of the motor. Oscillations of the system in resonances zones are analyzed, and relations between power input and dissipated power are estimated depending on the system parameters

Comparative analysis of two control algorithms of resonant oscillations of the vibration machine driven by an asynchronous AC motor

In this paper, the problem of automatic tuning of vibration technological machines (e.g. vibrating screens) to resonant mode is considered. The purpose of the study is to develop a control system to provide the initial resonant setup and its control, regardless parameters variations such as operating loads. To achieve this two control algorithms are proposed. The first algorithm is based on linear approximation, while the second one is based on the preliminary analysis of some relations between the system parameters. The advantages and disadvantages of the proposed algorithms are considered and the applicability limitations are determined

Self-synchronization features of inertial vibration exciters in two-mass system

The paper presents the results of experimental analysis features of rotation of two unbalance vibration exciters that excite oscillations of a chain-type two-mass oscillatory system in order to identify stability of synchronous modes of the debalances rotation near the system resonances (in application to analysis of resonant vibrating machines dynamics). Experimentally obtained amplitude-frequency characteristics of the model, velocities and mutual phase shift of rotation of the debalances are analyzed. Areas of stable synchronous rotation of the debalances and types of their self-synchronization are revealed as dependence of both the frequency of voltage supplying to the electric motors and the imbalances value. It is shown that when approaching the resonant frequencies, both the debalances rotational speeds and their mutual phasing appear to be unstable

Developing system of automatic control resonant mode of a vibrating machine

The paper is devoted to the experimental check of a control algorithm for automatic adjustment of oscillations of a mechanical system to the resonance mode. Oscillations of the system are excited by rotating an unbalanced rotor of an asynchronous electric motor. Working principle of the control system is based on measuring a phase shift between oscillations of the system and an excitation force