Wave propagation visualization through ducts using the Schlieren technique for crack localization with the eSHM...

Area of Science:

• Materials Science
• Mechanical Engineering
• Fluid Dynamics

Background:

• Additive manufacturing offers design flexibility for integrating smart technologies in components.
• Effective structural health monitoring (eSHM) systems analyze structural integrity of 3D printed parts.
• eSHM systems detect fatigue cracks using pressure wave propagation in embedded capillaries.

Purpose of the Study:

• To gain a deeper physical understanding of wave propagation within capillaries for improved crack localization accuracy.
• To validate computational fluid dynamics (CFD) simulations with experimental data.

Main Methods:

• Computational fluid dynamics (CFD) simulations were performed to model wave propagation.
• Experimental validation used Schlieren flow visualization and high-speed imaging techniques.
• Analysis focused on wave behavior, shock waves, and reflection mechanisms around simulated cracks/leaks.

Main Results:

• CFD simulations revealed propagating shock waves and contact discontinuities.
• Complex reflection mechanisms were observed around simulated leak locations.
• Schlieren experiments confirmed similar wave behavior and reflection patterns, validating the shock tube analogy.

Conclusions:

• Understanding wave dynamics, including shock waves and reflections, is crucial for accurate crack localization in eSHM systems.
• The study confirms the validity of using wave propagation analysis for structural health monitoring in 3D printed metallic components.
• The findings support the shock tube analogy for analyzing pressure wave behavior in eSHM systems.