1. Fluid Structure Interactions Research Group
Smart Materials and Structures with Hybrid Nonlinear Vibration Control for Marine Applications
Guanghong Zhu
Supervisors: Dr. Yeping Xiong, Prof. Steve Daley and Prof. R. A. Shenoi
Faculty of Engineering and the Environment
Motivation
For passenger ships (Figure 1), vibration and noise pollutions affect the comfort of passengers and crew members.
Vibration and noise generated by marine engines create pollutions, which harm the marine life and become one of the environmental problems.
New knowledge and technology need to be developed to address these problems by effectively controlling vibration transmission and acoustic noises.
Methodology
In order to further investigate dynamical properties of different MREs, it is necessary to perform multiple modes dynamic loading tests.
The nonlinear vibration theory considering the actual strain–stress relationship will be employed to establish mathematical model and predict the dynamic response of the MRE material and structure.
A hybrid passive/active vibration control system with adaptive MRE materials (Figure 3) will be investigated.
Nonlinear power flow approach will be developed to analyze the vibration energy transmission mechanism to evaluate the vibration control effectiveness.
Figure 1 Passenger ship
Background
When ship is travelling, ship structures experience complex and varying dynamic excitations and become the sources of noise radiations.
Magnetoryeological elastomers (MRE) consist of two parts: polymer matrix and active filler. Their mechanical properties can be controlled rapidly, continuously and reversibly by an external magnetic field (Figure 2).
Passive systems are not adaptive to the changing conditions; active ones consume a lot of energy and need a large activation force. It is showed that hybrid control systems are more effective.
Figure 3 A schematic hybrid control system
Programme
Experimental characterisation of the dynamical properties
Mathematical modelling of MRE materials and structures
Analyze vibration energy transmission and control mechanism
Practical design of hybrid vibration control system for applications
Figure 2 MRE without magnetic field and MRE under magnetic field
Aims
Develop the MRE materials to obtain greater MR effects, so as to expand their applications to large scale structures.
Design a vibration control system employing the dynamic properties of MRE material for marine applications.
Develop nonlinear power flow approach to analyse the energy transmission mechanism and evaluate the vibration control effectiveness.
Figure 4 Work programme
Challenges
Nonlinear mathematical model of MRE materials and structures under multiple loading modes .
Develop the nonlinear power flow approach to analyse the energy transmission mechanism of the smart nonlinear dynamical systems.
Develop hybrid active/passive control system to effectively control vibration energy transmissions.
FSI Away Day 2012
Acknowledgement: