Research On The Connector Of Very Large Floating Offshore Base

A new concept of Very Large Floating Offshore Base (VLFOB) is proposed for the application in deepwater oil and gas exploration and production in the South China Sea. The long distance from mainland and the abominable weather make the supply of materials difficult and the workers and facilities unsafe, the VLFOB can solve these problems because it will be used as a supply base and a harbor for the deep ocean work boats.The VLFOB is constructed by 8 single modules and the connectors between the modules are one of the key factors about the safty of the VLFOB. In this paper the loads on the connectors of the VLFOB are studied.The natural frequencies of the VLFOB with different connector stiffness are calculated by FEM method, and the corresponding results are analyzed by comparing them with the wave spectrum of 1-year,10-year,100-year and 1000-year environments in South China Sea. The results show that the VLFOB can avoid sympathetic vibration effectively by adjusting the stiffness of the connectors to be larger than 10000MN.The loads acted on the connector are calculated by numerical computation method and measured through the model tests in the ocean basin, the results show that the axial load and radial load on the connectors are closely related to the angle between connectors and the wave, the vertical load is not so closely. Besides, When the angle between connectors and the waves is between 0 degree and 30 degree, the axial load is very large.The axial load when the angle between connector and wave is 0 degree is the largest in 1-year, 100-year and 1000-year environments in South China Sea,and it is 29066t in 1-year environment and 96712.2t in 100-year environment...