Damage Analysis of Composite CFRP Tubes Using Acoustic Emission Monitoring and Pattern Recognition Approach

Area of Science:

• Materials Science
• Mechanical Engineering
• Non-Destructive Testing

Background:

• Carbon-fiber-reinforced polymer (CFRP) composites are crucial in various industries.
• Understanding damage mechanisms in CFRPs under mechanical stress is vital for structural integrity.
• Non-destructive testing (NDT) methods are essential for monitoring composite health.

Purpose of the Study:

• To detect and analyze damage mechanisms in CFRP tubes during three-point bending tests.
• To develop and validate a robust acoustic emission (AE) analysis technique for composite damage.
• To differentiate between various failure modes using AE signal characteristics.

Main Methods:

• Utilized the acoustic emission (AE) method for real-time monitoring of damage.
• Applied a two-step analysis technique combining unsupervised pattern recognition with short-time frequency spectra.
• Employed a boundary curve identification method based on tensile tests to filter AE signals.
• Correlated AE data with force and time dependencies to isolate damage sources.

Main Results:

• Successfully identified key failure mechanisms including matrix cracking, fiber break, decohesion, and debonding in CFRP tubes.
• The two-step AE analysis effectively filtered noise and isolated damage-specific signals.
• Parametric analysis of AE signals within identified clusters provided detailed insights into damage evolution.

Conclusions:

• The presented AE-based two-step method is effective for identifying diverse failure mechanisms in CFRP composites.
• The technique offers a reliable approach for non-destructive evaluation and damage assessment of composite structures.
• Findings contribute to a better understanding of composite failure under bending loads.