Choosing Damping Parameters for the Inertial Orientation System

2021 ◽  
pp. 113-128
Author(s):  
V.P. Podchezertsev ◽  
S.V. Topilskaya
Keyword(s):  
Natural Frequency ◽  
Vibration Suppression ◽  
Outer Space ◽  
Protection System ◽  
Dynamic Vibration ◽  
Shock Absorbers ◽  
Vibration Protection ◽  
Orientation System ◽  
Vibration Impact ◽  
Vibration Dampers

The article discusses criteria for selecting the vibration protection for the spacecraft inertial orientation system. The considered vibration protection system allows providing acceptable amplitude acceleration for the gyroscopic device sensitive elements under vibration impact on the device body during the spacecraft launching and high angular stability of the position of the sensitive elements relative to the inertial coordinate system during a long period of operation (15 years) in orbit. The proposed vibration protection system consists of shock absorbers (springs) with stable high elastic characteristics under all factors of operation in the outer space and dynamic vibration dampers. The article presents a method for determining the parameters of dynamic vibration dampers taking into account the characteristics of the shock absorber, critical for the damping system of an inertial device. The proposed method for adjusting dynamic vibration dampers consists in suppressing vibrations at the natural frequency f1 of the shock absorption system and providing acceptable values of the gain coefficients of the structure resonant vibration amplitudes near the natural frequency f1. Certain characteristics of the damping system allow realizing the permissible vibration amplification coefficients at resonance, without significantly affecting the level of vibration suppression in the natural frequency zone of the vibration protection object

scholarly journals A low cost electromechanical device injury model for hind limb murine muscles

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Daniel Perez-Hernandez ◽  
Bertha Segura-Alegria ◽  
Karla Garcia-Pelagio
Keyword(s):  
Hind Limb ◽  
Low Cost ◽  
Injury Model ◽  
Electromechanical Device

Design of an electromagnetic actuator for parametric stiffness excitation

2007 ◽  
Vol 26 (3) ◽  
pp. 800-813 ◽  
Author(s):  
Erich Schmidt ◽  
Wolfgang Paradeiser ◽  
Fadi Dohnal ◽  
Horst Ecker
Keyword(s):  
Finite Element ◽  
Permanent Magnets ◽  
Electromagnetic Actuator ◽  
Finite Element Analyses ◽  
Coil Current ◽  
Content Type ◽  
Electromechanical Device ◽  
Stiffness Variation ◽  
Actuator Design ◽  
First Time

PurposeAn overview is given on design features, numerical modelling and testing of a novel electromagnetic actuator to achieve a controllable stiffness to be used as a device for parametric stiffness excitation.Design/methodology/approachIn principle, the actuator consists of a current driven coil placed between two permanent magnets. Repellent forces are generated between the coil and the magnets, centering the coil between the two magnets. The 2D finite element analyses are carried out to predict the forces generated by this arrangement depending on coil current and coil position. Force measurements are also made using the actual device.FindingsActuator forces as predicted by the finite element analyses are in excellent agreement with the measured data, confirming the validity of the numerical model. Stiffness of the actuator is defined as the increase of force per unit of coil displacement. Actuator stiffness depends linearly on the coil current but in a nonlinear manner on the coil displacement. The performance of the actuator is sufficient to demonstrate the effect of a so‐called parametric anti‐resonance on a test stand.Research limitations/implicationsAlthough the performance of the actuator is satisfactory, there is potential for further improvement of the actuator design.Originality/valueThis paper reports for the first time on an electromechanical device to create a time‐periodic stiffness variation to be used for research in the field of parametrically excited mechanical systems. The device is used to prove experimentally an effect to suppress mechanical vibrations which has been studied so far only in theoretical studies.

Development of vibration system for decreasing of intensity of steel ladle outlet channel tightening

2021 ◽  
Vol 77 (2) ◽  
pp. 165-174
Author(s):  
S. P. Eron’ko ◽  
E. A. Ponamareva ◽  
E. S. Tsykhmistro
Keyword(s):  
Machine Building ◽  
Flow Section ◽  
Steel Ladle ◽  
General View ◽  
Technical Solution ◽  
Test Model ◽  
Outlet Channel ◽  
Hard Particles ◽  
Oscillation Process ◽  
Vibration Impact

The problem of tightening of outlet channel of steel ladle still remains relevant at present. A review of scientific and technical studies, aimed at elaboration of methods to keep the channel flow section constant presented. An analysis of deposition forming mechanisms on walls of outlet channel of steel ladle was done. To prevent their formation it was proposed to apply a vibration impact on the ladle shutter. Using simulation studies and specially elaborated methodology, the degree of influence and frequency of amplitude oscillations, acting along the ladle channel, on increasing speed of layer thickness formation on its walls and number of tearing off hard particles was established. To evaluate intensity of elastic waves absorption by the refractories of ladle shutter during vibration impact on it, a natural experiment was done. As a result of the experiment an initial information was obtained for determining parameters of oscillation process to guarantee effective functioning of the proposed casting facility. A necessity was established to account tenfold decrease of vibration acceleration during propagation of elastic wave along the casting channel from the lower end of collector nuzzle to the upper end of the ladle casting nozzle. Results of the complex studies became base of technical solution at elaboration of design of the ladle shutter. The elaborated shutter is equipped by a system of exciting vertically-directed oscillations, promoting decreasing intensity of hard particles sticking on the walls of the outlet channel. The design of the perfected ladle shutter and general view of its test model shown, which is equipped with the vertically-directed oscillations exciting system. Depending on capacity of the steel ladles, which can be from 100 to 300 t, their shutters can be equipped with one or several pneumatic plunger vibrators. Each of the plunger having the mass of 0.8 kg, can develop an impact force up to 300 N when supplying into its working cavity compressed air of 0.2 MPa pressure at flow rate 150 l/min. Industrial tests of the modernized shutter in a foundry shop of Yasinovatsky machine-building plant were done.

scholarly journals Investigating the Pre-Damaged PZT Sensors under Impact Traction

2018 ◽  
Vol 6 (4) ◽  
pp. 142 ◽  
Author(s):  
Sakineh Fotouhi ◽  
Mohamad Fotouhi ◽  
Ana Pavlovic ◽  
Nenad Djordjevic
Keyword(s):  
Sandwich Panel ◽  
Piezoelectric Sensors ◽  
Dynamic Loads ◽  
Impact Loads ◽  
Elastic Plates ◽  
Factors Affecting ◽  
Reliable Performance ◽  
Vibration Impact ◽  
Static And Dynamic Loads ◽  
Marine Applications

Ships are usually under vibration, impact, and other kinds of static and dynamic loads. These loads arise from water flow across the hull or surfaces, the propeller cavitation, and so on. For optimal design purposes and reliable performance, experimental measurements are necessary. These sensors are often used under or near the water, working conditions that improve the risk of sensor damage. This paper aims at investigating, by the use of finite elements, the behavior of damaged piezoelectric sensors under traction and impact loads. The numerical method was calibrated using results available in the literature regarding piezoelectric and elastic plates with a central crack. After calibration, the simulation was used on two types of Lead-Zirconium-Titanium oxide (PZT) sandwich panel structures reinforced by aluminum skins. The results proved that the damage size and impact energy are important factors affecting the response of piezoelectric sensors; therefore, special attention might be considered when using these sensors for marine applications.

Hardware Design of Electronic Ignition System for Special Electromechanical Device

2011 ◽  
Vol 58-60 ◽  
pp. 491-494
Author(s):  
Xiao Luo ◽  
Qing Sheng Luo ◽  
Yong Gang Cao ◽  
Lei Shi
Keyword(s):  
Circuit Design ◽  
Hardware Design ◽  
Safety Performance ◽  
Security Design ◽  
Control Module ◽  
Ignition System ◽  
Analog Switch ◽  
Electromechanical Device ◽  
Design Idea ◽  
Switch Circuit

The electronic ignition system for special electromechanical device is composed of control module, analog switch circuit, ignition driver module and ignition module. The key point to make the system work quickly, real time, safety and accurately is the hardware design. Study on electronic ignition circuit design for special electromechanical device considering security design is employed to effectively increase the reliability and safety performance, which corresponding design idea and technical way can lay a theoretical and technical foundation for subsequent research.

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