Note: Dynamic meso-scale full field surface deformation measurement of heterogeneous materials

Area of Science:

• Materials Science
• Mechanical Engineering
• Experimental Physics

Background:

• Understanding deformation and strain in granular materials is critical for predicting material failure.
• Heterogeneous materials exhibit complex local behaviors that are challenging to measure.
• Previous methods lacked the necessary temporal and spatial resolution for dynamic mesoscale analysis.

Purpose of the Study:

• To develop and demonstrate a dynamic experimental method for measuring local deformation and strain in granular materials at the mesoscale.
• To achieve high temporal and spatial resolutions for capturing dynamic events.
• To analyze strain heterogeneity and its implications for failure mechanisms in composite materials.

Main Methods:

• A dynamic experimental setup utilizing a high-speed camera and a high magnification extension tube.
• Application of the method to polymer bonded sugar crystals and glass beads filled epoxy particulate composites under dynamic loading.
• Full-field strain measurement across crystal boundaries and within crystals.

Main Results:

• Successful measurement of local strain and deformation fields at high temporal resolution.
• Demonstrated capture of local strain heterogeneity in both tested composite materials.
• Validation of the experimental method's capability to resolve fine-scale deformation.

Conclusions:

• The developed dynamic experiment provides critical data on local strain and deformation in granular materials.
• The method enables detailed analysis of crystal motion, rotation, and interface displacement.
• This technique is vital for elucidating local failure mechanisms in heterogeneous materials.