A Symmetry-Based Perspective Correction Method for High-Speed Deformation Analysis of Circular Blast-Loaded Plates.

Area of Science:

• Mechanics of Materials
• Structural Engineering
• Experimental Mechanics

Background:

• Dynamic response of plates to blast loading is crucial for protective structure design.
• Traditional methods like Digital Image Correlation (DIC) are effective but costly and complex.
• There's a need for simpler, cost-effective methods for specific structural responses.

Purpose of the Study:

• To develop and validate a monocular optical method for measuring transient out-of-plane displacement fields in circular plates under blast loading.
• To provide a low-cost alternative to stereo DIC for axisymmetrical structural responses.
• To reconstruct time-resolved displacement profiles without specialized stereo-optical instrumentation.

Main Methods:

• Utilized a single high-speed camera to record a diametral reference line on clamped circular aluminum plates subjected to blast loading.
• Applied perspective correction based on axisymmetric deformation to reconstruct displacement profiles.
• Validated optical reconstruction against 3D scanned post-test deformed shapes.

Main Results:

• Reconstructed displacement profiles closely matched 3D scan data.
• Achieved root-mean-square errors of 1.251 mm (6.57%) for Case A, 1.793 mm (9.20%) for Case B, and 1.043 mm (14.93%) for Case C.
• Demonstrated the effectiveness of exploiting symmetry for quantitative blast-response data.

Conclusions:

• A monocular optical method can accurately measure transient displacements in axisymmetrically loaded circular plates.
• This approach significantly reduces experimental cost and complexity compared to stereo DIC.
• Symmetry serves as a key principle for developing simplified, quantitative blast-response measurement techniques.