Health Monitoring of Bolted Spherical Joint Connection Based on Active Sensing Technique Using Piezoceramic...

Area of Science:

• Structural Engineering
• Materials Science
• Non-Destructive Testing

Background:

• Bolted spherical joints are critical components in space steel structures, influencing overall stiffness and load capacity.
• Connection looseness, stemming from fabrication errors or installation issues, can compromise structural integrity and lead to accidents.
• Internal bolting makes external detection of looseness in these joints challenging.

Purpose of the Study:

• To propose and validate active sensing methods for monitoring the tightness status of bolted spherical connections.
• To utilize piezoceramic transducers for detecting connection looseness in space steel structures.
• To ensure the safety and reliability of space steel structures during construction and service.

Main Methods:

• Fabrication of a bolted spherical joint specimen (triangle-on-triangle offset grid) for testing.
• Employment of Lead Zirconate Titanate (PZT) patches as both sensors and actuators to generate and detect stress waves.
• Application of wavelet packet analysis and time reversal (TR) methods to quantify signal energy and assess connection tightness.

Main Results:

• The energy of stress waves propagated through the connection is demonstrably affected by joint looseness.
• Wavelet packet analysis and TR methods effectively quantified signal energy, correlating it with connection tightness.
• Experimental results confirmed the effectiveness, repeatability, and consistency of the proposed monitoring methods.

Conclusions:

• The developed active monitoring method using PZT transducers is efficient for detecting bolted spherical joint tightness.
• The proposed technique shows significant potential for guaranteeing the safety of space steel structures.
• This non-destructive approach offers a reliable solution for maintaining structural integrity in critical applications.