Thermosonic Chladni figures for defect-selective imaging.

Area of Science:

• Materials Science
• Non-Destructive Testing
• Acoustics

Background:

• Conventional Chladni figures visualize vibration modes but offer limited defect characterization.
• Understanding energy dissipation in materials is crucial for defect detection.

Purpose of the Study:

• To experimentally observe and analyze thermosonic patterns from defects.
• To compare thermosonic patterns with conventional Chladni figures.
• To interpret thermosonic patterns using a hysteretic damping model.

Main Methods:

• Experimental observation of thermosonic patterns from simulated and realistic defects.
• Comparison with conventional Chladni figures.
• Analysis using a hysteretic damping model accounting for in-plane polarization.

Main Results:

• Thermosonic Chladni figures represent vibration energy dissipation patterns.
• Patterns are determined by the square of in-plane strain during resonant vibrations.
• Differences in nodal patterns arise from material extension-compression near boundaries.

Conclusions:

• Thermosonic imaging provides a novel approach to visualizing material defects.
• The hysteretic damping model accurately explains observed thermosonic patterns.
• Superposition of resonance modes enables comprehensive defect imaging.