Study of Vibration Control of Platform Structures

The jacket offshore oil platforms in ice infested area are vulnerable to the dynamic action of ice excitations. Ice-induced vibration of platform structures may cause structural failure, discomfort to workers or malfunction of equipments; hence, it is of practical interest to reduce the ice-induced structural responses. To improve ice resistant capacities of platform structures, vibration control techniques may be used. For instance, some passive and semi-active dissipation devices may be installed at platform structures to enhance vibration energy absorbing capacity. Ice excitations have some differences with wind and earthquake excitations. The control strategies are needed to investigate for platform structures under ice excitations. Passive, semi-active and active controls of offshore platform structures under ice excitation are investigated at State Key Lab of Structural Analysis of Industrial Equipment, Dalian University of Technology. The experimental arrangement, including the design of platform models and the moving table which simulates the response of real platform. In order to verify the validity of the device model, the moving table test of the large-scale mass damper was carried out. The excitatio