Environmental Effects on Piezoelectric Sensors Array Signals and a Compensated Damage Imaging Method

Area of Science:

• Materials Science and Engineering
• Mechanical Engineering
• Sensor Technology

Background:

• Piezoelectric sensor arrays offer high-resolution damage imaging for structural health monitoring (SHM).
• Environmental variations (e.g., temperature, humidity) can significantly impact the gain-phase characteristics of sensor array signals, affecting imaging accuracy.

Purpose of the Study:

• To experimentally evaluate the impact of environmental variations on piezoelectric sensor arrays.
• To develop and validate a compensated 2D-MUSIC algorithm for accurate damage imaging in composite structures under changing environmental conditions.

Main Methods:

• Detailed analysis of gain-phase differences in array signals due to environmental parameter changes.
• Development of an array error matrix to compensate the steering vector in the 2D-MUSIC algorithm.
• Application of the compensated 2D-MUSIC algorithm for iterative damage source localization and minimization of a cost function.

Main Results:

• Quantification of gain-phase variations in piezoelectric sensor arrays with respect to environmental parameters.
• Demonstration of the compensated 2D-MUSIC algorithm's ability to accurately estimate damage locations.
• Experimental validation on an epoxy laminate plate confirming the method's effectiveness.

Conclusions:

• The proposed compensated 2D-MUSIC method effectively mitigates environmental effects on piezoelectric sensor array signals.
• This approach significantly enhances the reliability and accuracy of damage imaging for structural health monitoring in composite materials.