Experimental Study of Deep Submersible Structure Defect Monitoring Based on Flexible Interdigital Transducer Surface...

Area of Science:

• Materials Science
• Acoustics
• Mechanical Engineering

Background:

• Deep submersibles require robust structural defect monitoring methods.
• Polyvinylidene fluoride interdigital transducers (PVDF-IDTs) offer potential for structural health monitoring due to their size and bonding capabilities.
• Understanding the impact of the underwater environment on PVDF-IDTs is crucial for their application.

Purpose of the Study:

• To investigate underwater surface acoustic wave (SAW) propagation using interdigital transducers (IDTs).
• To analyze the influence of underwater environments on IDTs with varying structures.
• To compare the effectiveness of Lamb waves versus Rayleigh waves for underwater structural health monitoring.

Main Methods:

• Numerical simulation using COMSOL software to determine underwater attenuation of IDTs and Lamb (A0 mode) waves on a titanium alloy plate.
• Experimental verification of simulation results.
• Analysis of acoustic attenuation at the solid-liquid interface.

Main Results:

• COMSOL software accurately predicts acoustic attenuation at the solid-liquid interface.
• Significant differences in underwater attenuation were observed for IDTs with different structures.
• Lamb waves demonstrated superior performance compared to Rayleigh waves for monitoring underwater thin plate structures.

Conclusions:

• PVDF-IDTs are suitable for structural health monitoring of underwater structures.
• The study provides essential design parameters for underwater interdigital transducers.
• Lamb waves are recommended over Rayleigh waves for effective health monitoring of underwater thin plate structures.