In order to find out and eliminate the safety hidden danger of ship tank structure strength and airtight performance, in addition to improving the level of ship construction and welding, it is critical to carry out tightness and strength test. It is found that the conventional strength test method has some disadvantages and is not suitable for every shipyard. Therefore, based on the FPSO project under construction, combined with the situation of Shanghai Waigaoqiao shipyard Wharf, the FPSO strength test optimization scheme will be put forward considering the economy and operability. Then NAPA software was used to check the floating state, structural strength and stability to verify the reliability of the strength test scheme.
In recent years, ship accidents happen frequently. According to the statistical results of accident investigation, more than 64% of accidents are caused by defects in the structural strength and tightness of ship tanks (Yang, 2012). Once there are defects in the structure and tightness of ship tank, it may lead to structural leakage, fracture, and even cause ship sinking and other serious consequences. In order to find and eliminate the hidden danger of strength and airtight performance of ship tanks as early as possible, shipyards should not only improve the level of shipbuilding and welding technology, but also carry out reliable airtight and structural strength tests to verify the watertight and airtight of the tank and the rationality of structural design (Gao, 2011). Strength test is the main mean to ensure the integrity of ship tank and prevent accidents. Therefore, according to the construction procedure of shipyard, the selection of suitable test method can reduce construction period and cost of the test (Huang, 2009).
Under the premise of full consideration of saving test cost and strong operability, the strength test schemes will need to be analyzed and studied. Therefore, based on the actual situation of Shanghai Waigaoqiao wharf and owner's requirements, this paper analyzes the logic of the test sequence, the scientific nature of the test scheme and the safety of the on-site implementation. The optimized scheme of FPSO strength test is proposed. Then based on the FPSO project under construction, NAPA software was used to loading in different test stages. At the same time, the buoyancy, structure strength and stability of FPSO are checked to verify the reliability of the strength test scheme.
