High frequency, multi-axis dynamic stiffness analysis of a fractionally damped elastomeric isolator using continuous system theory

2017 ◽  
Vol 389 ◽  
pp. 468-483 ◽  
Author(s):  
Luke Fredette ◽  
Rajendra Singh
Keyword(s):  
System Theory ◽  
High Frequency ◽  
Dynamic Stiffness ◽  
Continuous System ◽  
Stiffness Analysis ◽  
Elastomeric Isolator

Dynamic Stiffness Analysis of Concrete Pavement Slabs

1992 ◽  
Vol 118 (4) ◽  
pp. 540-556 ◽  
Author(s):  
N. McCavitt ◽  
M. R. Yates ◽  
M. C. Forde
Keyword(s):  
Dynamic Stiffness ◽  
Concrete Pavement ◽  
Stiffness Analysis

High Frequency Hydraulic Vibrators

1971 ◽  
Vol 13 (6) ◽  
pp. 380-383
Author(s):  
J. D. Smith
Keyword(s):  
Performance Prediction ◽  
High Frequency ◽  
Dynamic Stiffness ◽  
High Dynamic

Hydraulic vibrators which are powerful, cheap and compact are described and theory for their performance prediction is given. They are of use where high forces are required on structures of high dynamic stiffness at frequencies up to 1 kHz.

Approaches to Predicting the Vertical Transmissibility of a Suspension Seat With a Seated Subject

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Jun Wu ◽  
Meihuan Wang ◽  
Yi Qiu
Keyword(s):  
High Frequency ◽  
Dynamic Stiffness ◽  
The Other ◽  
Human Model ◽  
Apparent Mass ◽  
Frequency Range ◽  
Air Suspension ◽  
In Series ◽  
Inert Mass ◽  
Good Agreement

Abstract In this paper, four methods were put forward to predict the transmissibility of an air suspension seat with a seated subject. For characterizing the dynamics of the suspension seat, two of the methods were based on developing a model of the air suspension seat and calibrating the parameters using the transmissibilities of the suspension and complete seat respectively with an inert mass from the experiment. The other two methods substituted the detailed modeling of the seat by two dynamic stiffness connecting in series calculated from two same transmissibilities measured in the experiment. For characterizing the biodynamics of the human body, two of the methods took advantage of the normalized apparent mass from published papers to take the place of the human model, while the other two methods made use of one measured seat transmissibility with a subject to deduce the apparent masses of all the subjects. Good agreement was illustrated between the experiment and model prediction for all the four methods. In addition, it also exhibited that a large discrepancy can be resulted in, especially in the high-frequency range, if the seat model was substituted by one integrated dynamic stiffness.

Research on dynamic stiffness of the damping element in bellows-type fluid viscous damper by a simplified model

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaolei Jiao ◽  
Jinxiu Zhang ◽  
Hongchao Zhao ◽  
Yong Yan
Keyword(s):  
Frequency Domain ◽  
Analytical Model ◽  
High Frequency ◽  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Simplified Model ◽  
Viscous Damper ◽  
Content Type ◽  
Fluid Viscous Damper ◽  
Frequency Domains

Purpose Bellows-type fluid viscous damper can be used to isolate micro vibration in high-precision satellites. The conventional model cannot describe hydraulic stiffness in the medium- and high-frequency domain of this damper. A simplified analytical model needs to be established to analyze hydraulic stiffness of the damping element in this damper. Design/methodology/approach In this paper, a bellows-type fluid viscous damper is researched, and a simplified model of the damping element in this damper is proposed. Based on this model, the hydraulic stiffness and damping of this damper in the medium- and high-frequency domains are studied, and a comparison is made between the analytical model and a finite element model to verify the analytical model. Findings The results show that when silicone oil has low viscosity, a model that considers the influence of the initial segment of the damping orifice is more reasonable. In the low-frequency domain, hydraulic stiffness increases quickly with frequency and remains stable when the frequency increases to a certain value; the stable stiffness can reach 106 N/m, which is much higher than the main stiffness. Excessive dynamic stiffness in the high-frequency domain will cause poor vibration isolation performance. Adding compensation bellows to the end of the original isolator may be an effective solution. Practical implications A model of the isolator containing the compensation bellows can be derived based on this analytical model. This research can also be used for dynamic modeling and vibration isolation performance analysis of a vibration isolation platform based on this bellows-type fluid viscous damper. Originality/value This paper proposed a simplified model of damping element in bellows-type fluid viscous damper, which can be used to analyze hydraulic stiffness in this damper and it was found that this damper showed stable hydraulic stiffness in the medium- and high-frequency domains.

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