Buy article PDF
The purchased file will be sent to you
via email after the payment is completed.
US$ 35
|
Structural Engineering and Mechanics Volume 30, Number 6, December20 2008 , pages 679-698 DOI: https://doi.org/10.12989/sem.2008.30.6.679 |
|
|
|
Semi-active control of ship mast vibrations using magneto-rheological dampers |
||
Y.S. Cheng, F.T.K. Au and J.P. Zhong
|
||
| Abstract | ||
|
On marine vessels, delicate instruments such as navigation radars are normally mounted on ship masts. However the vibrations at the top of mast where the radar is mounted often cause serious deterioration in radar-tracking resolution. The most serious problem is caused by the rotational vibrations at the top of mast that may be due to wind loading, inertial loading from ship rolling and base excitations induced by the running propeller. This paper presents a method of semi-active vibration control using magneto-rheological (MR) dampers to reduce the rotational vibration of the mast. In the study, the classical optimal control algorithm, the independent modal space control algorithm and the double input-single output fuzzy control algorithm are employed for the vibration control. As the phenomenological model of an MR damper is highly nonlinear, which is difficult to analyse, a back-propagation neural network is trained to emulate the inverse dynamic characteristics of the MR damper in the analysis. The trained neural network gives the required voltage for each MR damper based on the displacement, velocity and control force of the MR damper quickly. Numerical simulations show that the proposed control methods can effectively suppress the rotational vibrations at the top of mast. | ||
| Key Words | ||
| magneto-rheological damper; neural network; semi-active control; ship mast; structural vibration. | ||
| Address | ||
| Y.S. Cheng: Dept. of Naval Architecture and Ocean Engineering, Huazhong University of Science and Technology, Wuhan 430074, P.R. China F.T.K. Au: Dept. of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China J.P. Zhong: Dept. of Naval Architecture and Ocean Engineering, Huazhong University of Science and Technology, Wuhan 430074, P.R. China | ||