Tension Force Estimation in Axially Loaded Members using Wearable Piezoelectric Interface Technique

Area of Science:

• Structural Health Monitoring
• Materials Science
• Mechanical Engineering

Background:

• Traditional methods for monitoring axial force changes in members often rely on statistical damage metrics that lack a direct physical correlation to the applied load.
• This limitation can hinder accurate quantitative estimation of axial force variations and structural integrity.

Purpose of the Study:

• To develop a novel wearable piezoelectric interface for quantitatively monitoring and estimating force changes in axially loaded members.
• To establish a new impedance-based force estimation method leveraging peak frequencies of impedance signatures.

Main Methods:

• Developed an impedance-based force estimation method correlating axial force levels with peak frequencies from a wearable piezoelectric interface.
• Designed and prototyped a wearable piezoelectric interface for easy integration with existing axial members.
• Validated the technique using numerical simulations of axially loaded cylindrical members and experimental assessment on a prestressed cable structure.

Main Results:

• The study established a relationship between axial force and peak frequencies in impedance signatures obtained from the wearable interface.
• Accurate prediction of axial force was found to be significantly influenced by the estimation of load transfer capability between the member and the interface.
• Feasibility was demonstrated through successful tension force change assessments in both numerical and lab-scale models.

Conclusions:

• The proposed wearable piezoelectric interface offers a promising, physically-grounded approach for quantitative axial force monitoring.
• The developed impedance-based method, considering load transfer, enhances the accuracy of force estimation in structural members.
• This technology has potential applications in structural health monitoring and maintenance of critical infrastructure.