Automatic ply-specific analyses of CFRP micrographs using shortest-path-based ply distinction

2026-06-17

AI Summary

This study addresses the challenge of automatically distinguishing individual ply instances in high-resolution microscopic images of carbon fiber–reinforced polymers (CFRP), where semantic boundaries between adjacent plies are often ambiguous. To this end, the authors propose a global information–driven shortest-path approach that transforms a semantic segmentation mask into a precise ply-level instance segmentation. By modeling the image as a graph and leveraging shortest-path algorithms, the method accurately delineates ply boundaries and assigns each fiber pixel to its corresponding ply—without requiring additional annotations. This enables quantitative analysis of local fiber volume fractions, ply thicknesses, and interlayer spacing. The approach demonstrates robust performance on CFRP images containing artificial gaps, complex stacking sequences, and through-thickness cracks, effectively visualizing and quantifying manufacturing-induced heterogeneities to support process optimization and structure–property correlation studies.

Abstract

We present an automated approach to distinguish between ply instances in semantic segmentation masks of high-resolution carbon-fiber reinforced polymer micrographs. Interpreting the segmentation mask as a graph with pixels as vertices, enables us to use a shortest-path algorithm yielding the ply-separating paths. Thereby, we bridge the gap between semantic segmentation and ply instance segmentation using global information. We successfully apply our approach on high-resolution micrographs featuring a broad range of characteristics like artificially added gaps in single or multiple plies, different stacking sequences and ply traversing cracks. Assigning each fiber pixel to a ply based on the calculated paths, allows for a comprehensive, quantitative ply analysis with respect to its microstructural properties like the local fiber volume fraction as well as locally resolved ply and interleaf layer thickness. These insights help to reveal manufacturing-induced inhomogeneities, draw conclusions on manufacturing parameters and link mechanical properties to underlying microstructural imperfections.

Problem

• ply instance segmentation
• CFRP micrographs
• semantic segmentation
• microstructural analysis
• fiber volume fraction

Innovation

• shortest-path algorithm
• ply instance segmentation
• carbon-fiber reinforced polymer
• microstructural analysis
• semantic segmentation