solids4foam: A toolbox for performing solid mechanics and fluid-solid interaction simulations in OpenFOAM

Full Changelog: v2.3...v2.4

Added in v2.4

• Added support for OpenFOAM-v2606, extending compatibility to OpenFOAM-v2312
  through OpenFOAM-v2606, alongside the existing OpenFOAM-9 and
  foam-extend-4.1 support.
• Added a configurable stabilisation framework, including combined
  stabilisation models, volumetric-strain-rate stabilisation, and PETSc SNES
  Jacobian support for JST and even-order schemes.
• Added high-order finite-volume solid mechanics, with high-order
  configurations for cantilever2d, Cook's membrane, pressurisedCylinder,
  plateHole, and sphericalCavity
  (https://doi.org/10.1016/j.jcp.2026.115056).
• Added a block-coupled incompressible solid formulation
  (https://doi.org/10.3390/app152312660).
• Added decomposeParMonolithic for consistently decomposing coupled meshes.
• Added adaptive time stepping to newtonIcoFluid.
• Added the solidPressureMinMax function object and utilities for detecting
  PETSc build state and summarising solver logs.
• Added an optional Unity build for libsolids4FoamModels, reducing
  compilation time.
• Added validation of the PETSc configuration at build time, continuous
  integration across supported OpenFOAM versions, and a v2512 Docker release
  image.
• Added further tutorial cases and per-tutorial README.md files, including the
  poroelasticity, elastoplasticity, ellipticPlate, and one-way cavity cases,
  plus expanded website documentation.

Changed in v2.4

• Tutorial cases are now stored in the OpenFOAM.com format and converted to
  foam-extend or OpenFOAM.org at run time, rather than the reverse. All three
  variants continue to work; see the upgrade notes below.
• Incremental (updated Lagrangian) solid models now stop with a clear message
  when an initial D field is present outside a restart; see the upgrade notes
  below.
• Improved IQN-ILS coupling and simplified FSI region selection.
• Extended electroMechanicalLaw with field-based active tension and
  independent fibre tensors.
• Made point-patch enforcement optional in the fixedDisplacement boundary
  condition, and made the fluidModel fluid-property accessors public.
• Unsupported foam-extend cyclicGgi patches now fail with a clear error
  rather than segfaulting during volume-to-point interpolation.
• Expanded regression coverage for solid, contact, FSI, and least-squares
  gradient cases, and added a Test-leastSquaresS4fGrad test application.

Fixed in v2.4

• Fixed PETSc Jacobian preallocation by creating the Jacobian as a block AIJ
  matrix, resolving segmentation faults with recent PETSc versions.
• Fixed old-time deformation gradient storage in StVenantKirchhoffElastic.
• Fixed least-squares gradient evaluation at boundary faces, and ported
  enhancedVolPointInterpolation to OpenFOAM-9, correcting rigid-rotation
  cases solved with the updated Lagrangian approach.
• Fixed the sign convention in the even-order Laplacian for the m == 0 case.
• Fixed boundary condition enforcement in the diffusionElastic mechanical law
  and the tabulated acceleration fields in sonicLiquidFluid.
• Fixed the RBFMeshMotionSolver setup for fluid-solid interaction, and
  documented a verified configuration.
• Fixed tmp<fvMatrix> assembly on OpenFOAM.org.
• Fixed the restart behaviour of the elasticWallVelocity boundary condition,
  which previously discarded its face-centre history and so restarted with a
  zero interface velocity. The history is now written to, and read from, the
  time directories, and is mapped by decomposePar and reconstructPar.

Removed in v2.4

• Removed tutorial-specific analytical solution function objects from
  src/solids4FoamModels; these now live in case-local libraries within the
  corresponding tutorials.

Upgrade notes for v2.4

• Tutorial case format: tutorial cases are stored in the OpenFOAM.com
  format. Cases copied from the repository run directly on OpenFOAM.com, and
  the Allrun scripts convert them for foam-extend and OpenFOAM.org. Local
  copies of older cases are unaffected, but any scripts that assumed the
  foam-extend layout (for example constant/polyMesh/blockMeshDict) should be
  updated.
• Initial D field with incremental solid models: incremental updated
  Lagrangian solid models solve for DD, and an initial D field alongside it
  can make boundary conditions pick up an inconsistent displacement history.
  Such cases now fail at startup unless the run is an explicit restart. Remove
  0/D from affected cases.
• Tutorial analytical solutions: if a case or user library referenced an
  analytical solution function object from libsolids4FoamModels, link against
  the case-local library in the corresponding tutorial instead.
• Interface-to-interface mapping and the undeformed mesh: all
  interface-to-interface mappings (AMI, GGI, RBF and directMap) now
  build the interface correspondence from the undeformed mesh points in the
  constant instance, rather than from the current interface. This keeps the
  correspondence independent of when it is first constructed, now that the
  cached interface geometry follows the mesh motion and the solid deformation.
  Cases whose mesh changes topology during the run, or whose points are not
  available in the constant instance, now fail with an explicit error instead
  of silently building the correspondence from whatever configuration the
  interface happened to be in. Previously, only AMI read the constant
  points, so this affects a wider set of cases than before.

Related to v2.4

• [beamFoam](https://github.com/solids4foam/beamFoam) was released alongside
  the v2.4 update (https://doi.org/10.51560/ofj.v5.170). It is developed and
  maintained in a separate repository and is not part of solids4foam itself.