Simulation of Hybrid Cathodic Protection System on Offshore Structures using boundary element method

Offshore structures’ complex and unique designs limit the performance of either sacrificial anode or impressed current cathodic protection. These obstacles lead to development of “Hybrid Cathodic Protection” which is devised to harness both methods benefits. In this study, the potential distribution between the anodes and the structures was determined by finding the solution to relevant systems of mathematical equations based on known boundary conditions. Firstly, BE (boundary element) method by using iso parametric linear quadrilateral elements on structure and Anodes, was used to define the systems of equations. Then, these equations were solved by a program written in FORTRAN language. Geometrical modeling, mesh generation, pre processing and post processing all were carried out by GID software. To facilitate data input, a user interface was developed in Delphi environment. A comparison between results of this program and a commercial FEM software and verification has been done. Finally, cathodic protection systems for some basic examples were designed by the proposed model and the results were cross checked with reality to show the reliability of the model.