New Generation Damping Technologies

Lead Research Organisation: University of Sheffield
Department Name: Automatic Control and Systems Eng

Abstract

The output frequency response is fundamentally important in the identification, analysis and design of linear systems in the frequency domain with many applications in control, communications, and vibration studies. This research investigation will extend these results by focusing on the output frequency response function [OFRF] for the Volterra class of nonlinear systems, which has recently been derived by the authors. The new OFRF concept reveals, for the first time, that for a wide class of nonlinear systems there is a simple polynomial relationship between the output spectrum and the time domain model parameters, which define the system nonlinearity. This provides the opportunity to analytically conduct optimal designs of nonlinear damping for both sdof and mdof systems, to determine the range of validity of the results, and to validate the new design technology using a vibration supression rig in the laboratory.

Publications

10 25 50
 
Description In mechanical, civil, and structural engineering, it is well-known that the increase of damping can often only improve the vibration control performance around resonance but is detrimental for the performance over higher frequencies. This project, for the first time, theoretically revealed that the use of odd powered nonlinear damping can systematically resolve this fundamental problem. The novel OFRF (Output Frequency Response Function) concept proposed by the research team and associated theories and methods are the very basis of this investigation. The results provide an important foundation for the development of effective solutions to a wide range of engineering structural vibration control problems.



In order to exploit the beneficial effects of nonlinear damping in engineering applications, the design and implementation of nonlinear damping have been conducted on several experimental systems including a BAE Systems test rig for marine vessel engine vibration isolation, providing novel and much better solutions to the structures' vibration control problems.
Exploitation Route The research findings have significant potential engineering applications. These include, for example, providing novel vibration isolation solution for generators and engines, and optimal placement and design of nonlinear dampers for more effective building vibration control during earthquakes etc. In these studies, the nonlinear damping was designed using the OFRF based nonlinear system design approaches and implemented by either active control device or semi-active MR dampers. These results provide a necessary basis for the application of nonlinear damping to resolve the vibration control problems of complex engineering structural systems such as, e.g., wind turbine towers and multi-storey buildings. The research team has already started collaboration with experts in these areas to apply the findings of this project to address relevant challenges.
Sectors Aerospace, Defence and Marine,Chemicals,Construction,Electronics,Energy,Manufacturing, including Industrial Biotechology,Other

 
Description The findings have been applied by both the PI 's research team and other researchers to address the vibration control problems in marine, wind energy, and earthquake engineering. For example, the PI's team is currently collaborating with researchers at Keio University in Japan to investigate the application of the novel nonlinear damping technology developed in this project to the design of semi-active isolation system for the Sosokan Building at Keio University.
Sector Construction
 
Description Royal Society International Exchanges Scheme
Amount £12,000 (GBP)
Funding ID IE150298 
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 08/2015 
End 12/2017
 
Description Royal Society International Joint Projects
Amount £11,190 (GBP)
Funding ID JP091396 
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 06/2010 
End 05/2012
 
Description Application of nonlinear damping technology in earthquake engineering 
Organisation Keio University
Country Japan 
Sector Academic/University 
PI Contribution Nonlinear damping technology
Collaborator Contribution Experimental facilities and expertise in earthquake engineering
Impact Two successful experimental studies have been completed . This is a very multi-disciplinary work involving system and control scientists and researchers in earthquake engineering .
Start Year 2015