A Post-Processing Method Based on Radial Basis Functions for the Fast Retrieval of the Strain Field in Digital Image...

Area of Science:

• * Solid Mechanics
• * Experimental Mechanics
• * Computational Mechanics

Background:

• * Digital image correlation (DIC) enables non-contact measurement of displacement and strain fields.
• * Traditional DIC post-processing often requires dense numerical grids and can be computationally intensive.
• * Existing methods may struggle with large deformation analysis.

Purpose of the Study:

• * To present a new post-processing strain evaluation method for DIC, specifically for large displacement problems.
• * To leverage Radial Basis Functions (RBF) for efficient and accurate strain computation.
• * To validate the proposed method against synthetic data and experimental results.

Main Methods:

• * Utilized Radial Basis Functions (RBF) for interpolating scattered displacement data obtained from DIC.
• * Employed the Green-Lagrange tensor for strain calculation, suitable for large deformations.
• * Developed a post-processing workflow independent of mesh generation.

Main Results:

• * The RBF-based method demonstrated faster convergence compared to Finite Element Methods (FEM) even with sparse data.
• * Accurate strain fields were computed directly from DIC displacement data without requiring a numerical grid.
• * The approach showed good agreement with experimental data from the literature for large displacement cases.

Conclusions:

• * The proposed RBF-based post-processing technique offers an efficient and accurate solution for strain evaluation in DIC, particularly for large displacements.
• * This method simplifies the analysis by eliminating the need for grid generation and provides reliable results.
• * The approach shows significant potential for advancing experimental mechanics and material analysis.