Work

3D fractal modeling of non-uniform corrosion in steel pipes: Failure behavior analysis and structural integrity assessment

Year: 2025

Type: article

Abstract: To address the limitations of conventional idealized geometric assumptions in evaluating the failure pressure of corroded steel pipes, this study proposes an integrated methodology combining three-dimensional (3D) fractal theory with finite element (FE) modeling to characterize the mechanical behavior of random non-uniform corrosion defects. A random non-uniform corrosion pipe model was developed by reconstructing corrosion morphologies using the Weierstrass-Mandelbrot (W-M) fractal function within a Python-ABAQUS collaborative framework, incorporating fractal dimension ( D n ), spatial frequency ( γ ), and scale coefficient ( C n ). The model's reliability was validated through full-scale burst tests. Systematic quantification revealed the correlation between geometric parameters of single-point defects, spacing of double-point defects, and failure behavior. The results demonstrate that under single-point corrosion conditions, increasing the defect length to 180 mm and depth to 0.8 t reduces failure pressure by 15.99 % and 23.66 %, respectively. Conversely, widening the corrosion angle to 40° reduces failure pressure by only 7.85 % through stress dispersion effects. For double-point corrosion interaction, longitudinal spacing exerts a significantly stronger influence on defect coupling than circumferential spacing. Critical spacings (1.5 D t for longitudinal alignment and 0.16π D for circumferential alignment) effectively isolate interaction effects. This study establishes a systematic correlation framework between fractal characteristics and mechanical responses, advancing a theoretical paradigm for the reliability assessment of corroded pipelines.

Source: Reliability Engineering & System Safety

DOI: 10.1016/j.ress.2025.111111