scholarly journals Implementation of the KDamper concept using disc springs

2018 ◽  
Vol 38 (1) ◽  
pp. 168-186
Author(s):  
Ioannis E Sapountzakis ◽  
Pavlos G Tranakidis ◽  
Ioannis A Antoniadis
Keyword(s):  
Structural Design ◽  
Vibration Isolation ◽  
Short Review ◽  
Optimal Combination ◽  
Negative Stiffness ◽  
External Excitation ◽  
Main Concept ◽  
Initial Displacement ◽  
Passive Vibration Isolation ◽  
Selection Of

The KDamper is a novel passive vibration isolation and damping concept, based essentially on the optimal combination of appropriate stiffness elements, which include a negative stiffness element. In this paper, after a short review of the optimal design and the selection of the parameters of the KDamper, the main concept focuses on the implementation of the negative stiffness elements with a set of Belleville (disc) springs. The major benefits of the proposed structure are the size and the robustness of the structure. The theory and the design process of the disc springs are presented thoroughly, as well as of the spiral springs with ground ends, along with an initial structural design. Simulation results from three different case scenarios are demonstrated; for an initial displacement, an initial velocity and an external excitation. The results obtained from the simulations show very satisfactory behavior.

An innovative X-shaped vibration isolation mount with tunable quasi-zero-stiffness property

2021 ◽  
Vol 263 (3) ◽  
pp. 3011-3022
Author(s):  
Jing Bian ◽  
Xingjian Jing ◽  
Yishen Tian
Keyword(s):  
Vibration Isolation ◽  
Negative Stiffness ◽  
Design Parameters ◽  
Property A ◽  
Vibration Displacement ◽  
Stiffness Property ◽  
Passive Vibration Isolation ◽  
Engineering Practices ◽  
Vibration Isolation Performance ◽  
Isolation Performance

Passive vibration isolation is always preferable in many engineering practices. To this aim, an innovative, compact, and passive vibration isolation mount is studied in this paper. The novel mount is adjustable to different payloads due to a special oblique and tunable stiffness mechanism, and of high vibration isolation performance with a wider quasi-zero-stiffness range due to the deliberate employment of negative stiffness of the X-shaped structure. The X-shaped structure has been well studied recently due to its excellent nonlinear stiffness and damping properties. In this study, by using of the negative stiffness property within the X-shaped structure, the X-shaped mount (X-mount) can have an obviously larger vibration displacement range which maintains the quasi-zero-stiffness property. A special oblique spring is thus introduced such that the overall equivalent stiffness can be much easily adjusted. Systematic parametric study is conducted to reveal the critical design parameters and their relationship with vibration isolation performance. A prototype and experimental validations are implemented to validate the theoretical results. It is believed that the X-mount would provide an innovative technical upgrade to many existing vibration isolation mounts in various engineering practices and it could also be the first prototyped mount which can offer adjustable quasi-zero stiffness conveniently.

Performance testing for an active/passive vibration isolation and steering system

1996 ◽  
Author(s):  
Jeanne Sullivan ◽  
James Gooding ◽  
Michelle Idle ◽  
Alok Das ◽  
Terance Hoffman ◽  
...  
Keyword(s):  
Vibration Isolation ◽  
Performance Testing ◽  
Steering System ◽  
Passive Vibration Isolation

scholarly journals Tilt Active Vibration Isolation Using Vertical Pendulum and Piezoelectric Transducer with Parallel Controller

2021 ◽  
Vol 11 (10) ◽  
pp. 4526
Author(s):  
Lihua Wu ◽  
Yu Huang ◽  
Dequan Li
Keyword(s):  
Piezoelectric Transducer ◽  
Vibration Isolation ◽  
Vertical Vibration ◽  
Open Loop ◽  
Negative Effects ◽  
Voltage Controller ◽  
Hysteresis Nonlinearity ◽  
Passive Vibration Isolation ◽  
Active Vibration ◽  
Active Vibration Isolation

Tilt vibrations inevitably have negative effects on some precise engineering even after applying horizontal and vertical vibration isolations. It is difficult to adopt a traditional passive vibration isolation (PVI) scheme to realize tilt vibration isolation. In this paper, we present and develop a tilt active vibration isolation (AVI) device using a vertical pendulum (VP) tiltmeter and a piezoelectric transducer (PZT). The potential resolution of the VP is dependent on the mechanical thermal noise in the frequency bandwidth of about 0.0265 nrad, which need not be considered because it is far below the ground tilt of the laboratory. The tilt sensitivity of the device in an open-loop mode, investigated experimentally using a voltage controller, is found to be (1.63±0.11)×105 V/rad. To compensate for the hysteresis nonlinearity of the PZT, we experimentally established the multi-loop mathematical model of hysteresis, and designed a parallel controller consisting of both a hysteresis inverse model predictor and a digital proportional–integral–differential (PID) adjuster. Finally, the response of the device working in close-loop mode to the tilt vibration was tested experimentally, and the tilt AVI device showed a good vibration isolation performance, which can remarkably reduce the tilt vibration, for example, from 6.0131 μrad to below 0.0103 μrad.

scholarly journals Procedure for the Selection of Rubber Compound in Rubber-Metal Springs for Vibration Isolation

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1737
Author(s):  
Milan Banić ◽  
Dušan Stamenković ◽  
Aleksandar Miltenović ◽  
Dragan Jovanović ◽  
Milan Tica
Keyword(s):  
Numerical Simulation ◽  
Constitutive Model ◽  
Vibration Isolation ◽  
Correct Selection ◽  
Virtual Experiment ◽  
Rubber Compound ◽  
Key Factor ◽  
Railway Engineering ◽  
Selection Of

The selection of a rubber compound has a determining influence on the final characteristics of rubber-metal springs. Therefore, the correct selection of a rubber compound is a key factor for development of rubber-metal vibration isolation springs with required characteristics. The procedure for the selection of the rubber compound for vibration isolation of rubber-metal springs has been proposed, so that the rubber-metal elements have the necessary characteristics, especially in terms of deflection. The procedure is based on numerical simulation of spring deflection with Bergström-Boyce constitutive model in virtual experiment, with a goal to determine which parameters of the constitutive model will lead to spring required deflection. The procedure was verified by case study defined to select rubber compound for a rubber–metal spring used in railway engineering.

Research and Application of High-Efficiency Multi-Cyclone Dust Removal

2011 ◽  
Vol 109 ◽  
pp. 400-404
Author(s):  
Yan Hong Yang ◽  
Da Fu Ni
Keyword(s):  
Structural Design ◽  
High Efficiency ◽  
Dust Removal ◽  
Working Principle ◽  
Selection Of

Performance and working principle of high-efficiency multi-cyclone were analyzed, and the structural design shortage of original high-efficiency multi-cyclone was pointed out. Its structure was researched and designed, including determination of setting chamber and pipe number, selection of material and the design of cyclones.

Exact analysis of the bending of wide beams by a modified elastica approach

2011 ◽  
Vol 225 (11) ◽  
pp. 2759-2764 ◽  
Author(s):  
L F Campanile ◽  
R Jähne ◽  
A Hasse
Keyword(s):  
Finite Element ◽  
Substantial Reduction ◽  
Short Review ◽  
Computational Effort ◽  
Two Dimensional ◽  
Finite Element Calculations ◽  
Dimensional Finite Element ◽  
Wide Beams ◽  
Insight Into ◽  
Selection Of

Classical beam models do not account for partial restraint of anticlastic bending and are therefore inherently inaccurate. This article proposes a modification of the exact Bernoulli–Euler equation which allows for an exact prediction of the beam's deflection without the need of two-dimensional finite element calculations. This approach offers a substantial reduction in the computational effort, especially when coupled with a fast-solving schema like the circle-arc method. Besides the description of the new method and its validation, this article offers an insight into the somewhat disregarded topic of anticlastic bending by a short review of the published theories and a selection of representative numerical results.

Application of MCDM-based TOPSIS method for the selection of optimal process parameter in turning of pure titanium

2017 ◽  
Vol 24 (7) ◽  
pp. 2009-2021 ◽  
Author(s):  
Akhtar Khan ◽  
Kalipada Maity
Keyword(s):  
Decision Making ◽  
Cutting Force ◽  
Pure Titanium ◽  
Cutting Speed ◽  
Optimal Combination ◽  
Depth Of Cut ◽  
Topsis Method ◽  
Content Type ◽  
Cp Ti ◽  
Selection Of

Purpose The purpose of this paper is to explore a multi-criteria decision-making (MCDM) methodology to determine an optimal combination of process parameters that is capable of generating favorable dimensional accuracy and product quality during turning of commercially pure titanium (CP-Ti) grade 2. Design/methodology/approach The present paper recommends an optimal combination of cutting parameters with an aim to minimize the cutting force (Fc), surface roughness (Ra), machining temperature (Tm) and to maximize the material removal rate (MRR) after turning of CP-Ti grade 2. This was achieved by the simultaneous optimization of the aforesaid output characteristics (i.e. Fc, Ra, Tm, and MRR) using the MCDM-based TOPSIS method. Taguchi’s L9 orthogonal array was used for conducting the experiments. The output responses (cutting force: Fc, surface roughness: Ra, machining temperature: Tm and MRR) were integrated together and presented in terms of a single signal-to-noise ratio using the Taguchi method. Findings The results of the proposed methodology depict that the higher MRR with desirable surface quality and the lower cutting force and machining temperature were observed at a combination of cutting variables as follows: cutting speed of 105 m/min, feed rate of 0.12 mm/rev and depth of cut of 0.5 mm. The analysis of variance test was conducted to evaluate the significance level of process parameters. It is evident from the aforesaid test that the depth of cut was the most significant process parameter followed by cutting speed. Originality/value The selection of an optimal parametric combination during the machining operation is becoming more challenging as the decision maker has to consider a set of distinct quality characteristics simultaneously. This situation necessitates an efficient decision-making technique to be used during the machining operation. From the past literature, it is noticed that only a few works were reported on the multi-objective optimization of turning parameters using the TOPSIS method so far. Thus, the proposed methodology can help the decision maker and researchers to optimize the multi-objective turning problems effectively in combination with a desirable accuracy.

Design of a Miniaturized Pneumatic Vibration Isolator With High-Static-Low-Dynamic Stiffness

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Yuhu Shan ◽  
Wenjiang Wu ◽  
Xuedong Chen
Keyword(s):  
Vibration Isolation ◽  
Dynamic Stiffness ◽  
Structure Design ◽  
Negative Stiffness ◽  
Vibration Isolator ◽  
Load Bearing Capacity ◽  
Compact Structure ◽  
Chamber Volume ◽  
Isolation Systems ◽  
Magnetic Rings

In the ultraprecision vibration isolation systems, it is desirable for the isolator to have a larger load bearing capacity and a broader isolation bandwidth simultaneously. Generally, pneumatic spring can bear large load and achieve relatively low natural frequency by enlarging its chamber volume. However, the oversized isolator is inconvenient to use and might cause instability. To reduce the size, a miniaturized pneumatic vibration isolator (MPVI) with high-static-low-dynamic stiffness (HSLDS) is developed in this paper. The volume of proposed isolator is minimized by a compact structure design that combines two magnetic rings in parallel with the pneumatic spring. The two magnetic rings are arranged in the repulsive configuration and can be mounted into the chamber to provide the negative stiffness. Then dynamic model of the developed MPVI is built and the isolation performances are analyzed. Finally, experiments on the isolator with and without the magnetic rings are conducted. The final experimental results are consistent with the dynamical model and verify the effectiveness of the developed vibration isolator.

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