Application of the coupled BEM/FEM method for calculation of cathodic protection system parameters

Abstract

Cathodic protection (CP) is a technique that prevents corrosion of underground metallic structures. Design of any CP system first requires defining the protection of current density and potential distribution, which should meet the given criterion. It also needs to provide, as uniform as possible, current density distribution on the protected object surface. Determination of current density and potential distribution of CP system is based on solving the Laplace partial differential equation. Mathematical model, along with the Laplace equation, is represented by two additional equations that define boundary conditions. These two equations are non-linear and they represent the polarization curves that define the relationship between current density and potential on electrode surfaces. Nowadays, the only reliable way to determine current density and potential distribution is by applying numerical techniques. This paper presents efficient numerical techniques for the calculation of current density and potential distribution of CP system based on the coupled boundary element method (BEM) and finite element method (FEM).

Sacrificial Anode Cathodic Protection System Modelling Using Direct Boundary Element Method

“…Scalar electric potential at any point of the homogeneous and isotropic electrolyte can be determined by solving Laplace partial differential equation [2,6,7]:…”

“…The relationship between the current density vector and the electric potential is given by Ohm's law, as follows [2,3,11]: ∇ where is current density vector and γ is electrolyte conductivity.…”

“…), placed in the electrolyte, are subject to the corrosion processes [1]. In order to protect against corrosive processes, passive protection (coatings) in combination with active electrochemical protection (cathodic protection) is most often applied to the metal infrastructure in the electrolyte [2]. The role of the cathodic protection system is slowing down or complete prevention of all corrosion forms from the metallic structure surface placed in the electrolyte [2].…”

“…In order to protect against corrosive processes, passive protection (coatings) in combination with active electrochemical protection (cathodic protection) is most often applied to the metal infrastructure in the electrolyte [2]. The role of the cathodic protection system is slowing down or complete prevention of all corrosion forms from the metallic structure surface placed in the electrolyte [2]. The cathodic protection system can be implemented as an imposed current cathodic protection system (ICCP) or as a sacrificial anode cathodic protection system (SACP) [3,4].…”

An accelerated boundary element method via cross approximation of integral kernels for large‐scale cathodic protection problems

“…Corrosion control is a critical factor for the remaining life of metallic structures and concrete, especially when they are exposed to corrosive environments, such as seawater, soil, and air of high humidity (Choi & Seo, 2009; Cusson et al., 2011; Kuntal et al., 2020). The use of coatings combined with cathodic protection (CP) systems (Mujezinovic et al., 2017), complemented by damage monitoring techniques (O'Byrne et al., 2014; Wang et al., 2015), is the standard practice for corrosion control. The CP system provides current to protect the metallic surfaces when coating breaks down and fails to provide protection against corrosion.…”