Study on the Ultimate Load Capacity of Cu-Ni Alloy Pipelines with Double Pitting Defects

Area of Science:

• Materials Science
• Mechanical Engineering
• Corrosion Engineering

Background:

• Pipelines made of copper-nickel (Cu-Ni) alloys are susceptible to pitting corrosion, which can compromise their structural integrity.
• Accurate assessment of the load-bearing capacity of pipelines with multiple defects is crucial for operational safety and maintenance.

Purpose of the Study:

• To investigate the influence of dual-defect morphological parameters on the ultimate load capacity of Cu-Ni alloy pipelines.
• To develop and validate an assessment model for predicting the load-bearing capacity of pipelines with double pitting corrosion defects.

Main Methods:

• Finite element simulation was employed to analyze the effect of defect parameters on ultimate load capacity.
• An assessment model was established based on single-pit defect models and simulation outcomes.
• Hydrostatic burst tests were conducted to validate the accuracy of the developed model.

Main Results:

• Ultimate load capacity increases with the distance between defect centers, approaching the capacity of a single defect with equivalent dimensions.
• The developed assessment model exhibits high predictive accuracy, with a maximum error margin of 3%.
• Failure in pipelines with double pitting defects is characterized by axial cracking and significant bulging deformation.

Conclusions:

• The proposed model provides a reliable method for predicting the ultimate load capacity of Cu-Ni alloy pipelines with double pitting corrosion.
• These findings offer significant engineering value for assessing the structural integrity of pipelines with real-world corrosion defects.