Digital volume correlation using a spherical shell template and cubic element for large rotation measurement.

Area of Science:

• Solid Mechanics
• Experimental Mechanics
• Computational Mechanics

Background:

• Digital Volume Correlation (DVC) is a key technique for non-destructive deformation measurement.
• Accurate measurement of large rotations in materials remains a challenge for existing DVC methods.
• The development of robust algorithms is crucial for analyzing internal material structures under complex loading conditions.

Purpose of the Study:

• To develop and validate a DVC method capable of measuring displacement fields under large rotation conditions.
• To enhance the robustness and applicability of DVC for analyzing internal material deformation.
• To provide a reliable tool for studying material behavior with significant rigid body motion.

Main Methods:

• Utilized eight-node cubic elements as the shape function for DVC.
• Employed the Newton-Raphson iterative method to solve the governing partial differential equations for displacement.
• Introduced a spherical shell template matching technique for integer-voxel displacement searching, ensuring rotation and translation invariance.
• Used simulated volume images for method verification.

Main Results:

• The proposed DVC method successfully measured displacement fields under arbitrary rigid body rotation angles.
• The spherical shell template matching provided optimal initial values for the Newton-Raphson method, improving convergence under large rotations.
• Simulated data confirmed the reliability and accuracy of the developed DVC approach.

Conclusions:

• The presented DVC method effectively measures deformation in materials experiencing large rotations.
• This technique is valuable for analyzing the internal structure deformation of materials under challenging conditions.
• The spherical shell template matching significantly improves DVC performance in large rotation scenarios.