The Stray Current Corrosion Research On The Ship Berthing At The Steel Sheet Dock

Ship and ocean structures often suffer from corrosions, one of which is the stray current corrosion. The stray current corrosion has been a problem that puzzled the ship yard and corporation in the whole world, not only in some developed countries, such as Japan and Europe countries, but also in some developing countries. It has caused tremendous economic loss. Recently many experts in this field have great interests in this problem, however, they have no way to solve this problem because of many complex affects on the corrosion. Therefore it is very important to do the further research on the stray current corrosion and find the way to solve it.The dock compares impressed current cathodic protection with sacrificial anode cathodic protection in five aspects: technical contrast, installation contrast, servicing contrast, developing trend contrast and economic contrast. Finally the dock uses impressed current cathodic protection to protect the dock from corrosion. In this process, the ship will suffer stray current corrosion. Based on this project, this thesis discusses the mechanism of the stray current corrosion and finds out the causes of the corrosion, which is called potential gradient.Firstly, study kinds of numerical calculation methods such as FEM and BEM. Compared with these methods, the thesis finally uses BEM to calculate the potential distribution and uses ANSYS soft to establish the electrostatic field numerical model and mesh generation model. Then find out the potential distribution of the electrostatic field using boundary element method. Finally, the thesis prevents the ship from stray current corrosion using two methods. The result of the thesis will provide help for further research in project.