In situ high-speed imaging dataset of microscale damage evolution in glass fibre-epoxy composites under quasi-static bending

This dataset contains high-speed, high-magnification images capturing microscale damage in glass fibre-epoxy composite laminates under in situ three-point bending. The data were acquired using a microscope-coupled high-speed camera at 25,000 frames per second, providing a spatial resolution of ~4 µm/pixel and a field of view of ~1.5 × 1 mm². Difference images, obtained by subtracting each frame from a reference image, are included to highlight evolving damage features. The dataset covers two laminate configurations: Single-90-ply ([0/90/0/0/0]S) and Double-90-ply ([0/90/90/0/0]S). Each configuration includes multiple specimens and image sequences capturing distinct stages of transverse crack initiation, propagation, fibre-matrix debonding, micro-delamination, and fibre breaks. The dataset structure is as follows.

Single-90-ply laminate
Specimen 1: Image sequence 1, 2, 3
Specimen 2: Image sequence 1, 2, 3
Specimen 3: Image sequence 1, 2, conventional images
Double-90-ply laminate
Specimen 1: Image sequence 1, 2
Specimen 2: Conventional images

The experimental setup follows the ASTM D7264 standard, using an inverted three-point bending configuration to stabilize the field of view and capture critical regions near mid-span. Laminates were prepared from Advantex® R25HX14 glass fibres in a thermoset epoxy matrix, cured in an autoclave, and polished to expose the microstructure for high-quality imaging. Loading was applied under displacement control at 1 mm/min, enabling the detection of rapid, transient damage events under quasi-static conditions. These high-speed sequences reveal the stepwise nature of transverse cracking, interactions with local defects, stress-shielding effects between adjacent cracks, and the progression toward final ply failure. The data also capture faster through-thickness propagation in Double-90-ply specimens and micro-delamination events associated with thicker ply blocks.

This dataset provides previously inaccessible insight into the dynamics of microscale damage in fibre-reinforced composites. It is intended to support the development and validation of mechanistic damage models, non-destructive evaluation strategies, and further experimental research on composite failure processes. All image sequences and corresponding difference images are included for detailed analysis and visualization. The dataset is linked to an article titled "New insights into damage dynamics in cross-ply laminates via high-speed, high-magnification imaging under quasi-static flexural loading".