Point load wave excitation in multi-layered solids: experiments and model verification

Area of Science:

• Solid Mechanics
• Wave Propagation Analysis
• Materials Science

Background:

• Understanding transient wave propagation in layered materials is crucial for structural health monitoring and non-destructive testing.
• Existing models often struggle to accurately capture complex wave behaviors in multi-layered solid structures.
• Experimental validation is essential to confirm the reliability of theoretical models.

Purpose of the Study:

• To introduce and validate a novel model for transient wave propagation in layered solid structures.
• To experimentally investigate wave propagation in single-layer, two-layer, and two-layer-on-half-space configurations.
• To compare experimental measurements with model predictions for diverse layered systems.

Main Methods:

• Development of a new analytical model for wave propagation in layered solids.
• Experimental setup involving point load excitation and surface displacement detection.
• Testing of single plates, aluminum-stainless steel two-layer structures, and a layered-on-half-space system (stainless steel/aluminum/acrylic).
• Characterization of transient source functions, including the pencil-lead-break source.

Main Results:

• The new wave propagation model demonstrated high accuracy across all tested configurations.
• Experimental results for transient displacements closely matched model predictions.
• The influence of layer order (e.g., aluminum atop stainless steel vs. stainless steel atop aluminum) on surface displacement was quantified.

Conclusions:

• The developed model provides a reliable tool for analyzing transient wave propagation in layered solids.
• Experimental validation confirms the model's effectiveness for single plates, two-layer structures, and layered half-spaces.
• This work advances the understanding and prediction of wave phenomena in complex solid materials.