Feasibility of Digital Image Correlation for Fatigue Cracks Detection under Dynamic Loading

Area of Science:

• Materials Science
• Mechanical Engineering
• Civil Engineering

Background:

• Railway infrastructure integrity is crucial for public safety.
• Non-destructive testing (NDT) methods are essential for early defect detection.
• Dynamic loading conditions pose unique challenges for rail inspection.

Purpose of the Study:

• To develop and validate a non-contact method for detecting defects in railway rails under dynamic loading.
• To combine digital image correlation (DIC) and finite element modeling (FEM) for enhanced defect analysis.
• To assess the sensitivity of the proposed method to artificial and fatigue cracks.

Main Methods:

• Utilized digital image correlation (DIC) to measure surface displacements and strains.
• Employed finite element modeling (FEM) to simulate rail behavior and validate experimental data.
• Tested rail samples with artificial and fatigue defects under cyclic loading conditions.

Main Results:

• The DIC-FEM approach demonstrated high sensitivity to fatigue cracks in railway rails.
• Accurate modeling of defect-free rails provided a reliable reference for experimental data.
• Validated experimental displacement and stress distributions with FEM predictions.

Conclusions:

• The proposed DIC-FEM technique is effective for non-contact, remote monitoring of railway rails.
• This method offers a sensitive approach for non-destructive testing of various components under dynamic loads.
• The integration of DIC and FEM enhances the reliability and accuracy of defect detection.