Predicting the coating condition on ships using ICCP system data

Abstract

SUMMARYThe condition of coatings on the metallic surface of the hull of a vessel changes over its lifetime due to the action of the sea, deterioration of the paint itself, damage caused by impacts, etc. Although increased current demand from an impressed current cathodic protection (ICCP) system can indicate the presence of damage, the location and extent is unknown. The position, size and the seriousness of the damage are important issues from mainly two points of view.• Corrosion: If the hull of the structure is corroded, the ship works inefficiently and can become dangerous from the crack initiation viewpoint.• Noisiness of the vessel: As the damage proliferates along the hull structure, the current flux from the anode to the cathode also increases. This increases the noise of the vessel and makes it more detectable to an enemy from the defence point of view.The goal of this work is to find a reliable method to discover the state of the coating of a vessel by using the commonly available data of its system of cathodic protection, ICCP.

Cathodic Protection of A Container Ship Using A Detailed BEM Model

“…2020, 8, x FOR PEER REVIEW 2 of 14 solved by discretizing only the under protection metallic surface. In the last few decades, BEM has been extensively used to solve sacrificial CP and ICCP problems mainly in ships [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], offshore and subsea structures [19,20], buried pipelines, underground structures, and steel-reinforced concrete [21], as well as optimization problems regarding the optimum placement of the anodes [8]. However, despite its advantages, the application of conventional BEM to large-scale problems suffers from very time-consuming computations and high demands for computer memory capacity.…”

“…The above-described CP problem can be solved efficiently with BEM. The advantage of the reduction of problem's dimensionality by one makes BEM an ideal tool for dealing with problems of infinite or semi-infinite domains [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”

“…A well-established and powerful numerical tool for analyzing cathodic protection problems is the boundary element method (BEM) [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. One remarkable advantage it offers is the reduction of the dimensionality of the problem by one.…”

“…Thus, although the electrochemical process occurs at the metallic surface and the surrounding electrolyte volume, cathodic protection (CP) problems can be solved by discretizing only the under protection metallic surface. In the last few decades, BEM has been extensively used to solve sacrificial CP and ICCP problems mainly in ships [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], offshore and subsea structures [19,20], buried pipelines, underground structures, and steel-reinforced concrete [21], as well as optimization problems regarding the optimum placement of the anodes [8].…”

Optimization of a ship’s ICCP system to minimize electrical and magnetic signature by mathematical simulation

“…The least squares of the potential on the element of the surfaces with respect to the potential target value of the surfaces were used as an objective function to smooth the potential [5,6]. Subject to the following constraints on the surface of the cathode [3] 0 min,…”