Jukka Aho 0ca159972e feat(backend): Complete tensor-based stiffness computation ...

Implement full 4th-order elasticity tensor approach in CPU backend:

- Fix topology extraction: extract_topology_type() returns type, then
  instantiate with node count N (was causing crashes)

- Implement basis derivative evaluation: get_basis_derivatives() call
  now works (BLOCKER resolved)

- Complete Jacobian transformation: J = ∑ X_k ⊗ dN_k/dξ using proper
  tensor outer products (Tensors.jl)

- Implement stiffness assembly: K_ij^{αβ} = ∫ (∂N_i/∂x_γ) C_{αβγδ}
  (∂N_j/∂x_δ) detJ dξ with double contractions

- Add basevec() helper for constructing unit vectors

NO B-matrix, NO Voigt notation - pure tensor mathematics following
golden standard (docs/src/book/multigpu_nodal_assembly.md).

This is the foundation for GPU implementation (same math, different backend).

2025-11-14 21:55:22 +02:00

..

abstract.jl

feat(backend): Add abstract backend system with Auto/GPU/CPU selection

2025-11-12 00:59:40 +02:00

cpu.jl

feat(backend): Complete tensor-based stiffness computation

2025-11-14 21:55:22 +02:00