Summarizing Time-Varying Digital Image Correlation Strain Fields Using Sankey Diagrams

2026-05-21

AI Summary

This study addresses the challenge that conventional digital image correlation (DIC) methods face in capturing the global temporal evolution of strain fields. To overcome this limitation, the work introduces Sankey diagrams into time-resolved DIC analysis for the first time. By extracting superlevel sets of the von Mises equivalent strain field and tracking spatiotemporal overlaps of connected components, the method enables temporal summarization and visualization of the emergence, persistence, merging, and disappearance of strain concentration regions. The approach is validated on tensile tests involving four distinct notch geometries, demonstrating its ability to concisely and effectively reveal material deformation mechanisms and precursors to failure, thereby significantly enhancing qualitative understanding of global strain evolution patterns.

Abstract

Digital Image Correlation (DIC) enables dense, time-resolved measurement of surface strain in deforming materials, providing insight into strain localization and failure mechanisms. However, the resulting strain fields are typically explored frame-by-frame through spatial visualizations, making global temporal patterns difficult to discern. We present a visual summarization approach that represents the evolution of high-strain regions as a single Sankey diagram constructed from superlevel sets of the von Mises equivalent strain field. By tracking connected components over time via spatial overlap, the diagram encodes the birth, persistence, merging, and disappearance of strain concentrations. Applied to four tensile test datasets with varying notch geometries, the approach compactly captures differences in deformation regimes and qualitative precursors to failure, complementing traditional spatial strain visualizations with a global temporal overview.

Problem

• Digital Image Correlation
• time-varying strain fields
• visual summarization
• temporal patterns
• strain localization

Innovation

• Sankey diagram
• Digital Image Correlation
• time-varying strain field
• superlevel sets
• strain localization