防食問題解析用軸対称境界要素法の開発と実験による検証

抄録

An axi-symmetric boundary element method (BEM) for corrosion problems was developed, in order to simplify the analysis of axi-symmetric fields such as pipes. The validity and usefulness of the axi-symmetric BEM were confirmed through the experiment and analysis of a cast iron-stainless steel galvanic system in a seawater pipe. Being compared with the 3D BEM, the axi-symmetric BEM permitted large reductions in numbers of elements and nodes, greatly simplified preparations for analysis, and further reduced CPU time.
Computational accuracy and CPU time were compared between the analyses using two approximation methods for polarization curves, i.e., logarithmic-approximation method and linear-approximation method. In the former a linear relation was assumed between the logarithm of current density and potential, and in the latter a linear relation between current density and potential. It was confirmed that the accuracy of the analyses using the both methods were sufficiently high at the same level, and the linear-approximation method was more advantageous for reduction in CPU time for complicated polarization curves than the logarithmic-approximation method.