DOI: 10.5281/zenodo.8256346
title: Accompanying data for the paper "Crack branching at low tip speeds: spilling the T"

description: Links

isCitedBy publication-article https://doi.org/10.46298/jtcam.10172
isSupplementedBy software https://archive.softwareheritage.org/swh:1:dir:73fae3c4e4fce0f9a2c36a7ccf3a7be7c229c5ca;origin=https://github.com/jrethore/ufreckles;visit=swh:1:snp:9c0d967db98cef7f2b5d1dca641d392f75794b80;anchor=swh:1:rev:c83ced7bf43f3bd717f85c82a39c8cce2a5515db
isSupplementedBy software https://zenodo.org/record/1433776
Language

English
License

Creative Commons Attribution 4.0
Contributions

Elie Eid contributed to the experiments, their analysis, the numerical simulations and the writing of the paper.
Rian Seghir contributed to the experiments and the fullfield measurements. He also contributed to the writing of the paper.
Julien Réthoré contributed to the experiments and to the writing of the paper.
Data collection: period and details

Data have been collected during July 2021
Funding sources

Connect Talent IDS project funded by Région Pays de la Loire, Nantes Métropole and Ecole Centrale de Nantes with the additional support of of European Union.
French Research National Agency programme through grant ANR-16-CE30-0007-01
Data structure and information

Four SCDC (Single Crack Direct Compression) specimens are dynamically loaded via an impact on the edge perpendicular to the notch.
Specimens are mounted on a waveguide to ensure proper compressive wave entering the specimen and to hold the sample while keeping all other boundaries free.
The impact induces a compressive wave; however, the presence of the hole creates a tensile zone sideways opening thus the notch and enabling the fracture initiation.
Due to the absence of an impedance at the right-hand side boundary, stress-waves are fully reflected from the right-hand side boundary and deliver new loading-unloading conditions of the crack-tip modifying its advancement eventually leading to branching.
Samples are laser-cut from a commercial PolyMethyl Methacrylate (PMMA) manufactured by Arkema. The pre-crack's width matches the beam's, ie. 200um. A synthetic speckle pattern is laser-engraved onto the sample surface (useful for ensuring quality and reproducibility of the pattern for the application of the DIC procedure).
All images are captured using the High-spatial Resolution and Ultra-high speed (HR-UHS) Cordin camera Model 580 at 400 kfps with a resolution of 3296 x 2472 pixels. Field of view is 154.25mm x 115.69mm leading to a pixel size of 0.0468mm.
Ufreckles is used to perform FE-based DIC using T3P1 linear triangular elements and a Tikhonov regularisation (over 3 elements). Eventually, Linear Elastic Fracture Mechanics (LEFM) parameters are obtained post-projecting displacement fields on Williams' series using Ufreckles.

https://zenodo.org/badge/DOI/10.5281/zenodo.1433776
https://archive.softwareheritage.org/badge/swh:1:dir:73fae3c4e4fce0f9a2c36a7ccf3a7be7c229c5ca/
Complete analysis of the data can be found in [Eid, E., Seghir, R., & Réthoré, J. (2023). Crack branching at low tip speeds: spilling the T. Journal of Theoretical, Computational and Applied Mechanics.]
All test directories contain:
Data

raw images: in /images/ folder in 16bit .tiff format
the timeline: at root (time.txt) in µs
a distortion model: at root (Distortion.mat) containing camera distortion modes and amplitudes for each camera sensor
a mesh: at root (mesh_crack_conform.vtk) for FE-based DIC
VTK result fields: in /Results/VTK/ containing experimental DIC mesh, nodal displacement, velocity and accelerations fields and elementary strain and strain-rate fields for each frame
Fracture parameters: in /Results/VTK/LEFM.txt containing the identified LEFM parameters (for the main crack propagation from initiation to branching frames)
Matlab Codes to produce results (working with Ufreckles)

MultiSensor_DIC_script.m: in /Codes/ is the main script to run DIC
Shape functions: in /Codes/shape_functions/ containing Zernike polynomial shape functions and deconvolution algorithm to get effective displacement from total displacement knowing camera distortions
One directory per tested specimen:

T3DE: impacted at a projectile velocity of 31.8 m/s
TAF1: impacted at a projectile velocity of 30.5 m/s
TAF2: impacted at a projectile velocity of 22 m/s
THOM: impacted at a projectile velocity of 22 m/s