A Design Method for Damped Vibration Absorber Considering Excitation Frequency Range : For General Excitation Force and Objective Function(Mechanical Systems)

Abstract A dynamic vibration absorber can be used for suppression of excessive amplitude of structures at the resonance. This paper deals with an optimal design method for the dynamic vibration absorber which consists of a mass and a carbon-black filled rubber vulcanizate. First, a system which consists of a main system and the dynamic vibration absorber was analyzed, considering nonlinear dynamic properties possessed by the rubber vulcanizate. Frequency response functions of the system were derived in the form including the rubber geometry and a mass ratio as design parameters. Next, an objective function was composed of the frequency response functions. Minimizing the objective function with respect to the parameters of the rubber geometry for given mass ratio, the optimal values were determined. From the consideration of the results, a new convenient method to determine the optimal values was derived. This method was examined by the experiments. As a result, the validity of the analysis method was verified, and the availability of the present design method for the suppression of vibration was confirmed.

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Optimization Research on Dynamic Balance of Spatial Engine under Limiting Shaking Moment

Materials Science Forum ◽

10.4028/www.scientific.net/msf.626-627.693 ◽

2009 ◽

Vol 626-627 ◽

pp. 693-698

Author(s):

Yong Yong Zhu ◽

S.Y. Gao

Keyword(s):

Mathematical Model ◽

Objective Function ◽

Kinetic Analysis ◽

Optimization Design ◽

Design Method ◽

Dynamic Balance ◽

Optimized Design ◽

Design Variables ◽

The Mathematical Model ◽

Shaking Moment

Dynamic balance of the spatial engine is researched. By considering the special wobble-plate engine as the model of spatial RRSSC linkages, design variables on the engine structure are confirmed based on the configuration characters and kinetic analysis of wobble-plate engine. In order to control the vibration of the engine frame and to decrease noise caused by the spatial engine, objective function is choosed as the dimensionless combinations of the various shaking forces and moments, the restriction condition of which presents limiting the percent of shaking moment. Then the optimization design is investigated by the mathematical model for dynamic balance. By use of the optimization design method to a type of wobble-plate engine, the optimization process as an example is demonstrated, it shows that the optimized design method benefits to control vibration and noise on the engines and improve the performance practically and theoretically.

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AN INDEPENDENT ACTIVE BALANCER FOR PLANAR MECHANISMS

Transactions of the Canadian Society for Mechanical Engineering ◽

10.1139/tcsme-2007-0011 ◽

2007 ◽

Vol 31 (2) ◽

pp. 167-190 ◽

Cited By ~ 1

Author(s):

Zhang Ying ◽

Yao Yan-An ◽

Cha Jian-Zhong

Keyword(s):

Working Conditions ◽

Design Method ◽

Design Procedure ◽

Vibration Absorber ◽

Planar Mechanisms ◽

Dynamic Balancing ◽

Joint Coupling ◽

Design Requirements ◽

Novel Concept ◽

Two Degree Of Freedom

This paper proposed a novel concept of active balancer for dynamic balancing of planar mechanisms. Somewhat similar to a vibration absorber, the active balancer is designed as an independent device, which is placed outside of the mechanism to be balanced and can be installed easily. It consists of a two degree-of-freedom (DOF) linkage with two input shafts, one of which is connected to the output shaft of the mechanism to be balanced by a joint coupling, and the other one is driven by a controllable motor. Flexible dynamic balancing adapted to different working conditions can be achieved by varying speed trajectories of the control motor actively. A design method is developed for selecting suitable speed trajectories and link parameters of the two DOF linkage of the balancer to meet various design requirements and constraints. Numerical examples are given to demonstrate the design procedure and to verify the feasibility of the proposed concept.

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Vibration control using a beam-like adaptive tuned vibration absorber with an actuator-incorporated mass element

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/09544062jmes1301 ◽

2009 ◽

Vol 223 (7) ◽

pp. 1555-1567 ◽

Cited By ~ 10

Author(s):

P Bonello ◽

K H Groves

Keyword(s):

Vibration Control ◽

Effective Mass ◽

Tuning Range ◽

Excitation Frequency ◽

Vibration Absorber ◽

Time Varying ◽

Additional Advantage ◽

Expected Performance ◽

Vibration Attenuation ◽

Tuned Vibration Absorber

An adaptive tuned vibration absorber (ATVA) can retune itself in response to a time-varying excitation frequency, enabling effective vibration attenuation over a range of frequencies. For a wide tuning range the ATVA is best realized through the use of a beam-like structure whose mechanical properties can be adapted through servo-actuation. This is readily achieved either by repositioning the beam supports (‘moveable-supports ATVA’) or by repositioning attached masses (‘moveable-masses ATVA’), with the former design being more commonly used, despite its relative constructional complexity. No research to date has addressed the fact that the effective mass of such devices varies as they are retuned, thereby causing a variation in their attenuation capacity. This article derives both the tuned frequency and effective mass characteristics of such ATVAs through a unified non-dimensional modal-based analysis that enables the designer to quantify the expected performance for any given application. The analysis reveals that the moveable-masses concept offers significantly superior vibration attenuation. Motivated by this analysis, a novel ATVA with actuator-incorporated moveable masses is proposed, which has the additional advantage of constructional simplicity. Experimental results from a demonstrator correlate reasonably well with the theory, and vibration control tests with logic-based feedback control demonstrate the efficacy of the device.

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A Framework for Component Layout and Geometry Design of Mechanical Systems: Configuration Network and its Viewing Control

Volume 1: 21st Design Automation Conference ◽

10.1115/detc1995-0068 ◽

1995 ◽

Author(s):

Kikuo Fujita ◽

Shinsuke Akagi

Keyword(s):

Design Method ◽

Mechanical Systems ◽

Optimization Procedure ◽

Computational Design ◽

Object Oriented Programming ◽

Design System ◽

Air Conditioner ◽

Programming Technique ◽

Geometry Design ◽

Component Layout

Abstract A Framework of computational design method and model is proposed for layout and geometry design of complicated mechanical systems, which is named “configuration network and its viewing control”. In the method, a design object is represented with a set of declarative relationships among various elements of a system, that is, configurations, which is gradually extended from schematic structure to exact layout and geometry through design process. Since a whole of such configurations forms a too complicated network to compute all together, how to view subparts is controlled based on levels of granularity and width of scope range. Such a configuration network is made to grow and refined through embodying geometry and layout corresponding to a focused subpart with a numerical optimization procedure. The framework has also an ability to flexibly integrate with engineering analysis. Moreover, a design system is implemented with an object-oriented programming technique, and it is applied to a design problem of air conditioner units in order to show the validity and effectiveness of the framework.

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Are Single Polymer Network Hydrogels with Chemical and Physical Cross-Links a Promising Dynamic Vibration Absorber Material? A Simulation Model Inquiry

Materials ◽

10.3390/ma13225127 ◽

2020 ◽

Vol 13 (22) ◽

pp. 5127

Author(s):

Leif Kari

Keyword(s):

Simulation Model ◽

Loss Factor ◽

Polymer Network ◽

Vibration Absorber ◽

Vibration System ◽

Frequency Range ◽

Dynamic Vibration Absorber ◽

High Loss ◽

Dynamic Vibration ◽

Cross Links

Tough, doubly cross-linked, single polymer network hydrogels with both chemical and physical cross-links display a high loss factor of the shear modulus over a broad frequency range. Physically, the high loss factor is resulting from the intensive adhesion–deadhesion activities of the physical cross-links. A high loss factor is frequently required by the optimization processes for optimal performance of a primary vibration system while adopting a dynamic vibration absorber, in particular while selecting a larger dynamic vibration absorber mass in order to avoid an excess displacement amplitude of the dynamic vibration absorber springs. The novel idea in this paper is to apply this tough polymer hydrogel as a dynamic vibration absorber spring material. To this end, a simulation model is developed while including a suitable constitutive viscoelastic material model for doubly cross-linked, single polymer network polyvinyl alcohol hydrogels with both chemical and physical cross-links. It is shown that the studied dynamic vibration absorber significantly reduces the vibrations of the primary vibration system while displaying a smooth frequency dependence over a broad frequency range, thus showing a distinguished potential for the tough hydrogels to serve as a trial material in the dynamic vibration absorbers in addition to their normal usage in tissue engineering.

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