Working on automated parameterised meshing of #FiniteElementAnalysis of periodic auxetic structures.
#Julialang #ComputationalMechanics #ComputationalDesign #Comodo #opensource
More on auxetic structures:
https://en.wikipedia.org/wiki/Auxetics
Built using the Comodo project:
https://github.com/COMODO-research/Comodo.jl
Playing with #FiniteElementAnalysis of an "expansion mesh" like structure. The geometry, mesh and boundary condition creation, as well as the FEA analysis, all occur automatically.
This simulation is still elastic, next step is to add plasticity.
So satisfying to finally reach 100% code coverage for testing!
Hoping to publish paper on Comodo by the end of the year. If you are into #ComputationalMechanics #Biomechanics #GeometryProcessing #FiniteElementAnalysis help to contribute to Comodo.jl and FEBio.jl and you'll be one of the authors!
Interesting paper by @jedbrown et al.
https://doi.org/10.48550/arXiv.2401.13196
For computational mechanics/physics, if you code by just punching in the equations from the textbooks directly, the physics should work, but computationally the way you evaluate the quantities may be unstable. This paper lists some recipes to avoid these.
Mostly small strain problem, but still feels icky to leave in.
![Figure 2 from the paper with the caption: "Relative error of standard computation of J–1 and its stable [equivalent]"](https://cdn.fosstodon.org/media_attachments/files/111/832/597/842/991/244/original/980281e4286cf61d.png "Figure 2 from the paper with the caption: \"Relative error of standard computation of J–1 and its stable [equivalent]\"")
Just a bit of #julialang looking ridiculously awesome :)
Based on #Ferrite by @koehlerson et al. https://ferrite-fem.github.io/Ferrite.jl/stable/
And say hello to Gibbon.jl, ongoing work towards a #JuliaLang implementation of the MATLAB toolbox GIBBON (https://www.gibboncode.org/. )
First pass at Gibbon.jl
https://github.com/gibbonCode/Gibbon.jl/
Blame It on the Sockets: Forensic Analysis of the Arecibo Collapse - Nearly three years after the rapid unplanned disassembly of the Arecibo radio tele... - https://hackaday.com/2023/08/29/blame-it-on-the-sockets-forensic-analysis-of-the-arecibo-collapse/ #finiteelementanalysis #neutronimaging #radiotelescope #engineering #collapse #forensic #arecibo #failure #spelter #socket #cable #news #zinc
New #preprint : "Experimental and Computational Analysis of Energy Absorption Characteristics of Three Biomimetic Lattice Structures Under Compression" https://arxiv.org/abs/2308.14452
#finiteelementanalysis #biomechanics #lattice
Saw a paper on a soft robotic star thing, and had to check. Yep I can confirm, it looks like it can grab things.
Paper: https://doi.org/10.1002/aisy.202200435
#opensource #FiniteElementAnalysis
Here is a link to my fully parameterized implemention with #FEBio + #GIBBON: https://www.gibboncode.org/html/DEMO_febio_0085_soft_robotic_star_01.html
GIBBON is ready for #CMBBE2023 ! Heading to Paris tomorrow and can't wait to present the latest implementations and upgrades for FEBio4.
If you are attending the workshop, upgrade GIBBON to the latest version:
https://www.gibboncode.org/
#opensource #biomechanics #FiniteElementAnalysis #ComputationalMechanics #MechanicalEngineering
Checking out "Taubin" smoothing. Looks great for smoothing voxel derived meshes. Video shows voxel mesh (red) of a femur and the Taubin smoothed surface retrieved (white).
One of Taubin's papers: https://doi.org/10.1109/ICCV.1995.466848
#opensource GIBBON implementation: https://www.gibboncode.org/html/HELP_smoothTaubin.html
Here the strain that you think you are applying (red curve) and the real strain in the middle layer (green curve) are plotted over time. As you can see a compressive Z-strain builds up during clamping which may offset the strain graph a lot.
Note this is Green-Lagrange strain. The linear tensile strain intended to be applied is 30%, the linear clamping strain is -30%.
#opensource #FiniteElementAnalysis
https://www.gibboncode.org/html/DEMO_febio_0065_clamp_tension_test.html
Indentation with a twist.
The rigid ball pushes into the rubber-like hyperelastic cube while also spinning. Friction then transfers torsional forces to the cube as well.
#opensource #GIBBON #FEBio #FiniteElementAnalysis
https://www.gibboncode.org/html/DEMO_febio_0028_sphere_indentation_friction_twist.html
New #openaccess #preprint with collaborators Shaiv Parikh et al.
"Biomechanical characterisation of thoracic ascending aorta with preserved pre-stresses"
https://doi.org/10.1101/2022.12.02.518810
Features some lovely automated meshing and #FiniteElementAnalysis with GIBBON
Here is a nice review paper on: "What Kelvin might have written about Elasticity"
https://doi.org/10.1111/j.1365-2478.2011.01049.x
And more on benefits for use with #FiniteElementAnalysis:
https://arxiv.org/pdf/1605.09606
A simple demo for automated design, meshing and #FiniteElementAnalysis of a hyperelastic tire in contact with a road surface.
#opensource GIBBON implementation: https://www.gibboncode.org/html/DEMO_febio_0079_tire_load_01.html
Lovely new paper by PhD student I co-supervise: Mahtab Vafaeefar (Twitter: @MahtabVfa)
Have a look if you are into: lattice structures, trabecular bone, #biomechanics and/or #FiniteElementAnalysis
"A Morphological, Topological and Mechanical Investigation of Gyroid, Spinodoid and Dual-Lattice Algorithms as Structural Models of Trabecular Bone"
#openaccess link
https://arxiv.org/abs/2211.13036
Journal link
https://doi.org/10.1016/j.jmbbm.2022.105584
Uses #opensource GIBBON codes for lattice structure+model creation
Automated meshing of a bifurcation (e.g. for blood vessel #FiniteElementAnalysis) with hexahedral elements using #opensource #GIBBON toolbox.
1) Take a cylinder
2) Cut a hole at bifurcation curve
3) Create direction vectors for surface "departure and arrival"
4) Use smooth bezier spline based lofting
5) Thicken quads to form hex. elements.
Demo rendered here:
https://www.gibboncode.org/html/DEMO_mesh_bifurcation_cut_loft_branch.html
Bezier approach was inspired by @acegikmo 's spline work
