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Source: examples/pffracture

Fracture examples overview

The upstream examples/pffracture folder is larger than the three fracture pages currently on the site. It contains small-strain phase-field fracture, finite-strain phase-field fracture, chemo-mechanical diffusion-fracture, and several multi-domain logo variants.

Detailed fracture pages already on the site

• PhaseFieldFracture: small-strain Miehe-type fracture. This corresponds to the MieheTensile2d.json and MieheShear2d.json family.
• NeoHookeanFracture: finite-strain phase-field fracture with neohookeanpffracture. This covers the neohookeanfrac-* family.
• DiffusionACFracture: chemo-mechanical diffusion and Allen-Cahn fracture. This corresponds to rect50grsdifffrac.json.

Additional files in this folder

• ACFracTensile2d.json: small-strain Allen-Cahn fracture with "type":"allencahnfracture" and linearelasticfracture material under tensile loading.
• ACFracShear2d.json: the same linear-elastic Allen-Cahn fracture model under shear loading.
• logo2d-tensile.json: 2D imported logo mesh with multiple allencahnfracture element blocks assigned to different domains.
• logo-rotation.json: 3D imported logo mesh with rotateddirichlet loading and multiple neohookeanpffracture domains.
• neohookeanfrac-2d-tensile.json and neohookeanfrac-2d-shear.json: 2D finite-strain tension and shear variants.
• neohookeanfrac-3d-tensile.json and neohookeanfrac-3d-tensile-check.json: 3D finite-strain tensile variants.
• rect50grsdifffrac.json: polycrystalline diffusion-fracture problem with many domain-specific element blocks.
• Geometry and mesh helpers: tensile.geo, shear.geo, tensile3d.geo, Tensile3D.geo, logo.geo, and logo2d.geo.

Representative input

ACFracTensile2d.json is the missing small-strain Allen-Cahn fracture variant that is not spelled out elsewhere on the site:

json { "dofs": { "names": ["d", "ux", "uy"] }, "elements": { "elmt1": { "type": "allencahnfracture", "dofs": ["d", "ux", "uy"], "material": { "type": "linearelasticfracture", "parameters": { "L": 1.0e6, "Gc": 2.7e-3, "eps": 0.012, "E": 210.0, "nu": 0.3, "stabilizer": 1.0e-6, "finite-strain": false } } } }, "postprocess": { "load": { "type": "sideaveragevalue", "dof": "uy", "side": ["top"] }, "reaction": { "type": "sideintegralrank2mate", "side": ["top"], "parameters": { "rank2mate": "stress", "i-index": 2, "j-index": 2 } } }, "job": { "type": "transient", "print": "dep" } }

Notes

• Small-strain fracture examples use linearelasticfracture or miehefracture.
• Finite-strain fracture examples use neohookeanpffracture.
• The logo examples are the best shipped references for repeating fracture element blocks across multiple named mesh domains.
• The fracture folder is also the main place where side and volume postprocessors are used to track load, reaction, area, and averaged crack-related quantities.