scholarly journals Experimental testing and modelling of a rotary variable stiffness and damping shock absorber using magnetorheological technology

2019 ◽  
Vol 30 (10) ◽  
pp. 1453-1465 ◽  
Author(s):  
Lei Deng ◽  
Shuaishuai Sun ◽  
Matthew D Christie ◽  
Jian Yang ◽  
Donghong Ning ◽  
...  
Keyword(s):  
Shock Absorber ◽  
Test Bench ◽  
Experimental Testing ◽  
Variable Stiffness ◽  
Test Results ◽  
Test Variable ◽  
Magnetorheological Damping ◽  
In Series ◽  
Variable Damping ◽  
Stiffness And Damping

This article presents a novel rotary shock absorber which combines the abilities of variable stiffness and variable damping by assembling a set of two magnetorheological damping units, one of which being placed in series with a rubber spring. This allows the damping and stiffness to be controlled independently by the internal damping and the external damping units, respectively. A test bench was established to verify the variable stiffness and damping functionality. The experimental results for variable damping test, variable stiffness test and co-working test are presented. At the amplitude of 10° and the frequency 0.5 Hz, increases of 141.6% and 618.1% are obtained for damping and stiffness separately if the corresponding current increased from 0 to 1 A and from 0 to 2 A, respectively. A mathematical model is then developed and verified to predict the changing of the damping and stiffness. The test results and the simulated model confirm the feasibility of the shock absorber with the ability of varying damping and stiffness simultaneously.

Semi-active vibration control of a transmission system using a magneto-rheological variable stiffness and damping torsional vibration absorber

2021 ◽  
pp. 095440702199949
Author(s):  
Wenfeng Li ◽  
Xiaomin Dong ◽  
Jun Xi ◽  
Xiong Deng ◽  
Kaiyuan Shi ◽  
...  
Keyword(s):  
Active Control ◽  
Torsional Vibration ◽  
Variable Stiffness ◽  
Transmission System ◽  
Vibration Absorber ◽  
Experimental Setup ◽  
Variable Damping ◽  
Independent Variable ◽  
Magneto Rheological ◽  
Stiffness And Damping

In this research effort, an innovative magneto-rheological variable stiffness and damping torsional vibration absorber (MR-VSDTVB) is proposed, and independent variable damping control and independent variable stiffness control are adopted to suppress the torsional vibration of the transmission system. MR-VSDTVB, based on semi-active control principle, exhibits a compact structure and integrates with magneto-rheological technology. First, the concept of MR-VSDTVB is discussed, and the output torque characteristic of MR-VSDTVB is analytically developed. Then, a prototype is fabricated and tested. A transmission system with MR-VSDTVB is proposed to verify the MR-VSDTVB's effectiveness. The structure and inherent characteristics of the transmission system are analyzed theoretically. Finally, an experimental setup of transmission system with MR-VSDTVB is built. Experimental results indicate that when torsional stiffness of MR-VSDTVB changes, a frequency shift phenomenon occurs; moreover, when torsional damping of MR-VSDTVB changes, the response amplitude of the experimental setup changes regularly; And finally, the on-off control test validates the effectiveness of semi-active control on the torsional vibration suppression of the transmission system. The above results verify the effectiveness of MR-VSDTVB in suppressing the torsional vibration of the transmission system. These findings are expected to expand the application of magneto-rheological technology and variable stiffness and variable damping technology in torsional vibration of transmission systems.

Semi-active vibration control of a rotating flexible plate using stiffness and damping actively tunable joint

2019 ◽  
Vol 25 (21-22) ◽  
pp. 2819-2833 ◽  
Author(s):  
Wei Hu ◽  
Yulong Gao ◽  
Xiaoqing Sun ◽  
Yikun Yang ◽  
Bintang Yang
Keyword(s):  
Large Amplitude ◽  
Low Frequency ◽  
Variable Stiffness ◽  
Experimental Results ◽  
Flexible Plate ◽  
Frequency Range ◽  
Amplitude Vibration ◽  
Variable Damping ◽  
Large Amplitude Vibration ◽  
Stiffness And Damping

Lighter structures are increasingly required for flexible spacecraft. However, low frequency and large amplitude vibration problems are unavoidable due to external disturbances or attitude maneuvering especially when working under a microgravity environment. Therefore, a new methodology involving a semi-active technique using an actively tunable joint with variable stiffness and damping control, capable of handling such issues is proposed in this study. The incentive active joint was conceived with a compact structure, based on the electromagnetic direct drive principle. First, a dynamic model of rotating flexible plate was established. Then, a prototype was fabricated and tested. Finally, on the one hand, numerical simulations and experimental results indicated that, when the joint torsional stiffness changed, a frequency shift phenomenon occurred. On the other hand, two types of noncontact periodic vibration excitation methods along the rotation direction were proposed and the experimental results validated that the major frequency bandwidth of interference signal was 0.08–0.52 Hz with a significant vibration attenuation of 5.5–31.5 dB in effective bandwidth. Moreover, in the low frequency range (0.08–0.43 Hz), variable damping was found to be the main factor and variable stiffness was the secondary factor. However, in the high frequency range (around 0.52 Hz), variable stiffness was dominant and variable damping was inferior. These findings are expected to effectively suppress the low frequency and large amplitude vibration of solar panels with flexible joints.

A Compact Variable Stiffness and Damping Shock Absorber for Vehicle Suspension

2015 ◽  
Vol 20 (5) ◽  
pp. 2621-2629 ◽  
Author(s):  
Shuaishuai Sun ◽  
Huaxia Deng ◽  
Haiping Du ◽  
Weihua Li ◽  
Jian Yang ◽  
...  
Keyword(s):  
Shock Absorber ◽  
Variable Stiffness ◽  
Vehicle Suspension ◽  
Stiffness And Damping

scholarly journals Development of a novel variable stiffness and damping magnetorheological fluid damper

2015 ◽  
Vol 24 (8) ◽  
pp. 085021 ◽  
Author(s):  
Shuaishuai Sun ◽  
Jian Yang ◽  
Weihua Li ◽  
Huaxia Deng ◽  
Haiping Du ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Magnetorheological Fluid ◽  
Magnetorheological Fluid Damper ◽  
Fluid Damper ◽  
Stiffness And Damping

Experimental and Theoretical Rotordynamic Characteristics of a Hybrid Journal Bearing

1997 ◽  
Vol 119 (1) ◽  
pp. 132-141 ◽  
Author(s):  
J. T. Sawicki ◽  
R. J. Capaldi ◽  
M. L. Adams
Keyword(s):  
Journal Bearing ◽  
Operating Conditions ◽  
Dynamic Force ◽  
Test Results ◽  
Force Measurements ◽  
Lubrication Equation ◽  
Load Cells ◽  
Theoretical Predictions ◽  
Stiffness And Damping

This paper describes an experimental and theoretical investigation of a four-pocket, oil-fed, orifice-compensated hydrostatic bearing including the hybrid effects of journal rotation. The test apparatus incorporates a double-spool-shaft spindle which permits independent control over the journal spin speed and the frequency of an adjustable-magnitude circular orbit, for both forward and backward whirling. This configuration yields data that enables determination of the full linear anisotropic rotordynamic model. The dynamic force measurements were made simultaneously with two independent systems, one with piezoelectric load cells and the other with strain gage load cells. Theoretical predictions are made for the same configuration and operating conditions as the test matrix using a finite-difference solver of Reynolds lubrication equation. The computational results agree well with test results, theoretical predictions of stiffness and damping coefficients are typically within thirty percent of the experimental results.

Application of Magneto Rheological Dampers for Controlling Shock Loading

1999 ◽  
Author(s):  
Mehdi Ahmadian ◽  
James C. Poynor ◽  
Jason M. Gooch
Keyword(s):  
Dynamic System ◽  
Shock Loading ◽  
Closed Loop ◽  
Shock Absorber ◽  
Mr Damper ◽  
Test Results ◽  
Closed Loop System ◽  
Mr Dampers ◽  
Shock Dynamics ◽  
Magneto Rheological

Abstract This study will examine the effectiveness of magneto-rheological (MR) dampers for controlling shock dynamics. Using a system that includes a 50-caliber rifle and a magneto-rheological damper, it is experimentally shown that MR dampers can be quite effective in controlling the compromise that commonly exists between shock forces and strokes across the shock absorber mechanism. A series of tests are conducted to demonstrate that different damping forces by the MR damper can result in different shock-force/stroke profiles. The test results further show that MR dampers can be used in a closed-loop system to adjust the shock loading characteristics in a manner that fits the dynamic system constraints and requirements.

Development of an Experimental Device to Study Real Connecting-Rod Bearings Functioning in Severe Conditions

2007 ◽  
Vol 129 (3) ◽  
pp. 647-654 ◽  
Author(s):  
Philippe Michaud ◽  
Aurelian Fatu ◽  
Bernard Villechaise
Keyword(s):  
General Principle ◽  
Test Bench ◽  
Numerical Models ◽  
Experimental Device ◽  
Test Results ◽  
Connecting Rod ◽  
Compression Loading ◽  
Key Points ◽  
Loading System

The paper presents a new experimental device made to analyze the thermoelastohydrodynamic (TEHD) behavior of connecting-rod bearings functioning in severe conditions. First, it focuses on the test bench description. The general principle of the test bench and then the main original technological solutions used with respect to the functional specifications are detailed. Two numerical models are described. They were developed in order to design and to validate two central components of the experimental device. Finally, the paper comments on the test results used to understand and validate the traction∕compression loading system, which is one of the key points in the test bench behavior.

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