Vibration reduction by energy transfer using shape adaption

Vibration reduction by energy transfer using shape adaption

(Third Party Funds Group – Sub project)

Overall project: SPP 1897: Calm, Smooth and Smart - Novel Approaches for Influencing Vibrations by Means of Deliberately Introduced Dissipation
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Start date: 1. January 2016
End date: 31. December 2019
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Funding source: DFG / Schwerpunktprogramm (SPP)
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Abstract

Lightweight design is one of the most important issues in engineering design. The objective is to reduce the mass of structural components for the purpose of saving costs, energy and resources in manufacturing and operation processes. However, the lighter the structure is, the more it is prone to unwanted vibrations. Such vibrations should be minimized in order to prevent the environment, products and human beings from being harmed and to maximize the lifetime of the products.Vibration reduction can be achieved by passive, semi-active or active measures, where passive means that no external energy is needed, while semi-active and active measures employ external energy to either control dissipation or directly counteract the vibrational motion, respectively. Since active measures usually do not rely on dissipation, they do not fall in the scope of the call for proposals and will not regarded in this project. In the realm of passive and semi-active measures, two general approaches can be used to reduce vibration in structures, namely that of damping, which is the dissipation of kinetic energy into another form of energy, or that of absorption, which is the transfer of kinetic energy from a critical mode into an uncritical mode.The envisioned approach will combine the concepts of damping and absorption in a novel way by integrating the functionality of a damped, tuned mass absorber into a shape adaptive structure. By dynamically adapting the stiffness of a slender, beam-like structure using shape adaption of the cross-section, kinetic energy will be transferred from the critical low-frequency bending modes into a specifically designed, higher frequency absorber mode, which can then be damped in an optimal way. Optimal design of the shape adaption mechanism and of the absorber mode will be pursued using compliant mechanisms. The dissipation will be optimized by a specifically designed friction damper.

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