Cell Biology JoVE (Open Access) Citable · DOI

Crack Monitoring in Resonance Fatigue Testing of Welded Specimens Using Digital Image Correlation

Name: Crack Monitoring in Resonance Fatigue Testing of Welded Specimens Using Digital Image Correlation
Uploaded: 2026-07-14
Duration: 5 min 30 s
Description: A procedure using digital image correlation (DIC) to detect cracks on welded specimens during fatigue tests on resonance testing machines is presented. It ...

DOI: 10.3791/60390-v

What you'll learn

✓ Apply digital image correlation to monitor crack propagation in fatigue tests
✓ Prepare and instrument welded specimens for resonance fatigue testing
✓ Interpret strain data to detect and track macroscopic crack initiation and growth
✓ Post-process DIC data to visualize fatigue failure mechanisms

Protocol

Biopharma Insights Digital image correlation is used in fatigue tests on a resonance testing machine to detect macroscopic cracks and monitor crack propagation in welded specimens. Cracks on the specimen surface become visible as increased strains.

Difficulty

advanced

Total time

~4–8 hours per specimen (including setup, fatigue test duration varies by material/loading)

Steps

Prepare welded specimens for testing

Prepare welded specimens and apply surface preparation (cleaning, speckle pattern coating, or markers) required for digital image correlation tracking.

▶ 00:39

Set up resonance fatigue testing machine

Mount specimen in resonance testing machine, position DIC camera(s), calibrate optical system, and verify lighting and focus on the specimen surface.

▶ 01:25

Execute resonance fatigue test cycle

Run fatigue test at resonance frequency while simultaneously recording digital image correlation data; monitor in real-time for crack initiation and growth.

▶ 02:22

Post-process DIC strain and displacement data

Analyze captured DIC image sequences to compute strain maps, correlate increased strain regions with crack locations, and extract quantitative crack propagation metrics.

▶ 03:16

Interpret and visualize fatigue crack results

Present strain evolution, crack initiation point, propagation rate, and final fracture morphology using DIC-derived visualizations and quantitative data.

▶ 03:59

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