Simulation of oscillation dynamics of vibroprotective system with the electrorheological shock-absorber

The paper presents development of a mathematical model of a three-mass oscillating vibroprotective system with electrorheological (ER) shock-absorber by taking into account influences of temperature and electric field. Performance characteristics of the ER shockabsorber are established including dependences of force on rod displacement for different absorber geometry, rheological properties of ER fluid and magnitudes of temperature and electric field. This research work also provides comparison of simulation results of ER vibroprotective system during its linear movement through road profile “the sleeping policeman” in time domain. Amplitude-frequency characteristics of the vibroprotective system with ER shock-absorber are determined as function of electric field strength and temperature

Electrosensitive glue for vibrotesting of radioelectronic industry items

The possibility of using electrocontrolled glue (ER glue) for fixing radioelectronic industry items during their vibrotesting is discussed. The schemes are presented for fixing items of different materials and shapes to the electrodes of the basic surface of the fixing device. The impact of technological factors is demonstrated to enable us to obtain an increase in the specific fixing force sufficient for mounting the items in order to conduct experiments in the required range of vibro-acceleration

Compositional materials with controllable vibration damping parameters

The paper proposes laminated sandwich-elements containing electrorheological composite as a structural element, which enable designing novel thin-wall structures with a locally varying rigidity and vibrostability for aerospace engineering, ship-building, high-speed devices in mechanical engineering (machine tools, robots), in transport means (controlled springs), in instrument fabrication, et

Simulation of oscillation dynamics of mechanical system with the electrorheological shock-absorber

The paper presents the development of mathematical model of oscillating system by taking into account electrorheological (ER) characteristics. Characteristics of the ER shock-absorber (dependences of force on value of control electric signal considering shock-absorber geometry, rod displacement, rheological properties of ER fluid) are calculated. Comparison of simulation results of shock-absorber characteristics with experimental findings is performed. Analysis of calculated relations of amplitudes of output and input signals depending on value of a control electric signal is carried ou

Simulation of Performance Characteristics of a Magnetorheological Shock-Absorber at the Dependence of Rheological Properties from the Magnetic Field

The mathematical model of a magnetorheological shock-absorber taking into account of the dependence of rheological properties from the magnetic field is developed. Performance characteristics of the MR shock-absorber (dependences of force on value of control electric signal taking into account of shock-absorber geometry, rod displacement, rheological properties of MR fluid) are calculated. The analysis of influence of control electric signal value on MR shock-absorber performance characteristics depending on amplitudes and frequencies of piston movement is carried out

Identification of Nedd4 E3 Ubiquitin Ligase as a Binding Partner and Regulator of MAK-V Protein Kinase

MAK-V/Hunk is a scantily characterized AMPK-like protein kinase. Recent findings identified MAK-V as a pro-survival and anti-apoptotic protein and revealed its role in embryonic development as well as in tumorigenesis and metastasis. However molecular mechanisms of MAK-V action and regulation of its activity remain largely unknown. We identified Nedd4 as an interaction partner for MAK-V protein kinase. However, this HECT-type E3 ubiquitin ligase is not involved in the control of MAK-V degradation by the ubiquitin-proteasome system that regulates MAK-V abundance in cells. However, Nedd4 in an ubiquitin ligase-independent manner rescued developmental defects in Xenopus embryos induced by MAK-V overexpression, suggesting physiological relevance of interaction between MAK-V and Nedd4. This identifies Nedd4 as the first known regulator of MAK-V function

Controllable vibro – protective system for the driver seat of a multi – axis vehicle

The paper considers a controlled vibration protection of the multi-axis vehicle with hydraulic shock absorbers that are based on “smart” fluid. The dependence is experimentally determined for the viscous and elastic components of the resistance force of the electrorheological fluid as a function of intensity of the electric field. Investigation of vertical oscillations of the system “workplace-driver” with a controlled vibro-protection system is provided. The dependence is established for the relative displacement of weight as function of external perturbation at different values of the control signal

The peculiarities of ultrasound wave propagation in magnetorheological fluid with complex dispersive phase

This work is devoted to experimental study of the peculiarities of ultrasound wave propagation in magnetorheological fluid (MRF) with complex disperse phase under evaluation of changing of ultrasonic waves (UW) velocity in MRF on the base of water, oxide powder and carbonyl iron particles vs. intensity of applied magnetic field have been obtained. It was found that in the result of magnetic field separation the oxide layer thickness of MRF is increasing with the field value and can be determined by 2-3 µm and lesser

Dynamics of vibroprotecting system when using controlled damping fluids with hereditary factor

Oscillating system with a damper containing controlled damping fluid with hereditary electrorheological characteristics was investigated. Numerical calculation of the system in quasistationary approximation was carried out to prove the accuracy of applied assumptions

Calculations of electrical fixing device for vibrotesting of electronic components

The description of the device with the electrical sensitive glue to fix components of electronic devices (capacitors, resistors, chips) at their trials on harmonic and shock loads with the aid of shaker table is presented. Based on the polarization forces of interaction of the filler particles in the structure of the electrical glue we have performed a simulation and calculation of the limiting values of fixing forces of the component with the electrode of the mounting devices. Parameters of the electric field corresponding to the utmost full transmission of vibrations to the component are determined