Remaining Strength Calculation Method of Corroded Pipeline with Interaction of Double Pitting Defects

The remaining strength of corroded pipeline with double pitting interaction was analyzed to verify the reliability of the analytical method by the nonlinear finite element analysis method. A failure pressure calculation method of double pitting pipeline was estabished. Based on that, the impact of axial spacing on residual strength of pipeline with double pitting of the same sizes and different sizes was studied. The results showed that there was no completely mutual action between double pitting. Double pitting interaction was logarithmically changed with axial spacing, but there was no change in double pitting interaction if pitting diameter and depth were the same. However, the interaction range of different pitting sizes decreased with the increase of pitting diameter or depth gap. The fitting interaction coefficient in double pitting can reasonably predict the interaction of two pitting defects, and solve the calculation of failure pressure of pipeline with double interaction pitting defects.