A Proposed Non-Destructive Method Based on Sphere Launching and Piezoelectric Diaphragm

Area of Science:

• Materials Science
• Mechanical Engineering
• Non-Destructive Testing

Background:

• Acoustic emission (AE) is a valuable technique for monitoring material integrity.
• Traditional AE methods like pencil-lead break (PLB) can suffer from inconsistency.
• Developing reproducible and reliable AE methods is crucial for structural health monitoring.

Purpose of the Study:

• To develop and evaluate a reproducible acoustic emission (AE) method using a metallic sphere impact.
• To compare the repeatability and effectiveness of the sphere impact method against the traditional pencil-lead break (PLB) test.
• To assess the AE method's capability in damage detection for different material structures.

Main Methods:

• A novel AE method was developed utilizing a metallic sphere launched by a low-cost piezoelectric diaphragm.
• Comparative tests were performed on carbon fiber-reinforced polymer (CFRP) and aluminum structures.
• The proposed sphere impact method was compared with standard pencil-lead break (PLB) tests under varying impact conditions.

Main Results:

• The sphere impact AE method demonstrated significantly higher repeatability compared to the PLB method.
• The PLB method showed greater susceptibility to human error and variability.
• Both methods were effective in detecting damage, but the sphere impact method offered more consistent results.

Conclusions:

• The metallic sphere impact method provides a more reproducible and reliable approach for acoustic emission testing.
• This method is a viable alternative to PLB for damage detection in composite and metallic materials.
• The findings support the adoption of this improved AE technique for structural health monitoring applications.