Optimization of Cathodic protection system by Boundary Element Method

提出了一种确定阴极保护系统中最佳外加电流密度和最佳电极位置的边界元法。电解质内的电位由具有非线性边界条件的Poison方程描述，所述非线性边界条件是基于实验确定的电化学极化曲线来强制执行的。在保护结构各部位电位均小于某一临界值的保护条件下，确定了最佳外加电流密度，使保护电源最小。采用共轭梯度法求解，并利用罚函数法考虑了保护条件，提出了将共轭梯度法应用于真实的复杂结构的若干技巧。为了科普三维问题计算时间长的问题，提出了一种求导数的有效方法， ...更多信息 f电位，这是优化过程中所需要的。对于电极必须直接位于结构壁上的结构，对边界积分方程进行了修正，使设计变量与边界元网格无关，从而避免了通常优化过程中每次迭代都要重新划分网格的问题，发展了一种有效的三维边界元法，用于预测电-机械耦合过程中的电-机械耦合问题。由细长部件组成的结构的电流场响应。为分析一台由数千根不锈钢管与黄铜板连接的换热器的电偶腐蚀问题，提出了另一种有效的方法。利用模糊集和边界元法求解了由远离金属表面的点的电位值估计金属表面电流密度的反问题。用边界元法处理了腐蚀问题中涂层缺陷的识别问题。少

A boundary element method for determining the optimum impressed current densities and optimum location of electrode in a cathodic protection system was developed. The potential within the electrolyte was described by poison's equation with nonlinear boundary conditions which were enforced based on experimentally determined electrochemical polarization curves. The optimum impressed current densities were determined in order to minimize the power supply for protection under the protecting conditions that the electric potential of every part of the structure to be protected should be less than some critical value. The solution was obtained by using the conjugate gradient method in which the protecting conditions were taken into account by the penalty function method.Several techniques were proposed to apply the above method to a real complicate structure. In order to cope with the long cpu time for three dimensional problem, an effective method was proposed for obtaining the derivatives o … More f potential, which were needed in the optimizing procedures. For structures in which the electrodes must be located directly on the walls of the structures, the boundary integral equation was modified in such a way that the design variables become independent of the boundary element mesh in order to avoid the remeshing which was necessary in each iteration in the usual optimization procedures.An effective three dimensional boundary element method was developed for predicting electro-galvanic field response of a structure which consists of slender parts. Another effective method was developed to analyze the galvanic corrosion problems of a heat exchanger which had thousands of stainless pipes connected to the brass plate. The inverse problem where the density of the current across the metal surface was estimated from the potential values measured at some points far from the metal surface was solved by using the fuzzy set and boundary element method. The identification of coating defect in corrosion problems were also treated by usung the boundary element method. Less