Real-Time Fatigue Crack Growth Monitoring Using High-Precision Control and Data Acquisition Systems

Accurate real-time monitoring of fatigue crack growth is essential for understanding crack propagation behavior under cyclic loading and predicting material failure in critical structures. This session provides a detailed comparison of four widely used crack growth monitoring techniques: Digital Image Correlation (DIC), Acoustic Emission (AE), Compliance-Based Methods, and Direct Current Potential Drop (DCPD). Each technique is evaluated for its accuracy, resolution, sensitivity to noise, and performance under various environmental conditions.

Key metrics such as detection thresholds and resolution limits are discussed to guide the selection of the most suitable technique for specific applications. DIC, for example, provides high-resolution surface strain measurements, but is limited by optical line-of-sight requirements. AE is highly effective for early-stage crack detection but prone to false positives due to environmental noise. Compliance-based methods offer reliable crack length measurements in well-defined geometries, while DCPD excels in high-temperature, high-pressure environments due to its stability and resistance to electromagnetic interference.

The session will also explore how modern data acquisition and high-precision control systems enhance the integration of these techniques, enabling real-time multi-sensor data fusion and improving crack growth predictions. Examples from aerospace, nuclear power, and transportation infrastructure will illustrate how these advanced monitoring systems reduce downtime, prevent catastrophic failures, and extend the lifecycle of critical components.

Attendees will gain practical insights into selecting the most appropriate tools and combining multiple techniques to improve crack growth monitoring and prediction accuracy.