The Vibration Control Experimental Study Of Offshore Platform Structure With Rockingcolumn With Sector Lead Viscoelastic Dampers

With the improving of the overall national strength and the economic level,our country has a growing demand for oil and gas resources.The energy all over the world is focusing on the development of Marine resources,the blue ocean strategic plan which is proposed by our nation relies on offshore platforms-the important basic facility.With the development of offshore oil and gas field,sea ice has become the main control load of the engineering structure design of oil and gas exploration and development in the Bohai Sea.In this paper,the general finite element software ANSYS was used to analyze the JZ20-2 North High Point wellhead jacket platform,lifted the resistance to ice of platform structure by applying the sector lead viscoelastic damper to the offshore platform-rocking column structure system,made some valuable reference of resisting ice on the offshore platform.The main works are as follows:1.For the offshore platform-rocking column structure 1:10 scale model existed in Qingdao Technological University,the finite element model was established through ANSYS,design the parameter of sector lead viscoelastic damper in accordance with the offshore platform lateral stiffness and structure damp.The simulation results showed that the stiffness and damp of damper is the key parameters for vibration reduction under the loads of ice.Rocking architecture can not only keep the displacement tends on a consistent level,but also consume rotational energy further through the sector lead viscoelastic damper on hinge point,achieve better effect of vibration reduction.2.Made experiment on hysteretic behavior of three damper specimens which have the same size but different parameters,concluded the influence factors of its energy dissipation by comparing the parameters such as energy dissipation coefficient,equivalent damping ratio and so on.3.Three finite element models of dampers which have the different parameters were established by ANSYS,and did the simulation analysis under the shear displacement.After contrasting the simulation with the experiment results and the analysis of the damper bone curve,it showed that the damper mechanical model is similar to bilinear model and proved that the damper simulation with BISO is feasible.4.Applied the sector lead viscoelastic damper to the Connecting rod and the swinging column hinge point and reduced the rocking column stiffness at the same time,made analysis of economic efficiency when the two different platform forms get the same vibration reduction under the loads of ice,it could reduce the cost of offshore platform-rocking column system,provide a economic reference for structure vibration.