Contactless and Vibration-Based Damage Detection in Rectangular Cement Beams Using Magnetoelastic Ribbon Sensors

Area of Science:

• Materials Science
• Structural Health Monitoring
• Non-Destructive Testing

Background:

• Structural integrity monitoring is crucial for civil engineering applications.
• Early crack detection in cementitious materials prevents catastrophic failures.
• Existing methods may be invasive or lack sensitivity to micro-cracks.

Purpose of the Study:

• To investigate the efficacy of magnetoelastic sensors for detecting single cracks in cement beams.
• To analyze the changes in bending mode spectra caused by crack formation.
• To determine the sensitivity and influencing factors of this non-invasive detection technique.

Main Methods:

• Cement beams were subjected to bending vibrations with and without induced cracks.
• Magnetoelastic sensors were attached to the beams, and their signals were non-invasively detected.
• Changes in the bending mode spectrum were analyzed to identify crack presence and characteristics.

Main Results:

• A significant change in the sensing signal (24% per 1% volume loss) indicated crack detection.
• Pre-annealing sensors and using steel supports enhanced signal detection.
• The method provided qualitative information regarding crack location.

Conclusions:

• Magnetoelastic sensors offer a sensitive, non-invasive approach for detecting small cracks in cement beams.
• The technique is influenced by sensor pre-treatment and support material.
• This method holds promise for structural health monitoring of concrete structures.