Permeability Sensors for Magnetic Steel Structural Health Monitoring.

Area of Science:

• Materials Science
• Non-destructive Testing
• Mechanical Engineering

Background:

• Structural health monitoring (SHM) is crucial for magnetic steels.
• Residual stress and strain are key indicators of crack initiation.
• Accurate measurement of these parameters is essential for safety and maintenance.

Purpose of the Study:

• To present novel magnetic permeability sensors for SHM of magnetic steels.
• To establish the relationship between magnetic properties and residual stress/strain.
• To compare new sensor technologies with traditional methods.

Main Methods:

• Determination of magnetic stress calibration (MASC) curves.
• Measurement of differential magnetic permeability.
• Development and testing of Hall effect and anisotropic magnetoresistive (AMR) sensors.
• Comparison with single sheet testers and electromagnetic yokes.

Main Results:

• Good agreement found between magnetic properties and residual stress/strain.
• Established MASC curves and a Universal MASC curve.
• Demonstrated the effectiveness of differential magnetic permeability for monitoring stress/strain distribution.
• Highlighted advantages of new low-power sensors.

Conclusions:

• Magnetic permeability is a reliable indicator for SHM in magnetic steels.
• Novel Hall effect and AMR sensors offer promising alternatives for stress/strain monitoring.
• The developed sensors provide a low-power, effective solution for SHM applications.