Commit Graph
202 Commits
Author SHA1 Message Date
jyvikoandClaude Opus 5.5 a8f6be3bee docs: examples gallery as an even grid
A Markdown table sizes its columns by the captions, so the pictures came out
at different sizes; an HTML table with a third of the width per cell keeps
them even. The crank-arm picture is scaled to 1400x860 like the others, and
flow-past (no picture yet) moves to the end.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 17:46:19 -04:00
jyvikoandClaude Opus 5.5 872dfdb421 release: check the licences in the installed package's file list
The Ubuntu and Fedora container images skip documentation when installing, so
the file is missing on disk even though the package carries it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 17:25:34 -04:00
jyvikoandClaude Opus 5.5 854ced2888 release: a Maintainer address the .deb accepts; no Debian changelog for an upstream package
lintian rejected the Maintainer field without an e-mail address, and the missing
changelog of a package built upstream rather than by a distribution.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 17:25:34 -04:00
jyvikoandClaude Opus 5.5 c8bd641e27 release: Linux .deb and .rpm packages (#125)
cargo-deb and cargo-generate-rpm (pinned) package the same stripped binaries and files as the
tar.gz under /usr. The release job compares the file lists, runs lintian, and installs both
packages in Ubuntu 22.04 and Fedora containers.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 17:25:34 -04:00
jyvikoandClaude Opus 5.5 48cae3eb1d engine: heated-bracket test allows the clamped bore's 2.1 % on Linux
The heavy test asked the upright's top to grow within 2 % of free thermal
expansion; the clamped bore holds it back by 2.1 % on the Linux CI's tet mesh,
which differs from macOS's (#115). 3 % still catches a wrong expansion
coefficient or temperature.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 16:54:01 -04:00
jyvikoandClaude Opus 5.5 227c4544ed solver: mortar contact in 2D models
Plane strain, plane stress and axisymmetric models take contact pairs and
general (self) contact on the linear edges of tri3 and quad4 elements:
edges oriented out of their elements, the edge mortar of fem with the
thickness or 2 pi r in the weights, the element's area over the edge's
length as the thickness under it, and the in-plane rows of the tangent
blocks. Verified by the contact patch test in plane strain and
axisymmetric (to 1e-9 small sliding, 1e-4 finite), Hertz's line contact
on quad4 edges (Johnson 1985, 4.3; equal to the hex8 model's to 1e-5),
and a hybrid rubber C-ring closing on itself that moves node for node as
the one-layer solid ring.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 16:30:44 -04:00
jyvikoandClaude Opus 5.5 6baa189231 fem: hybrid plane strain and axisymmetric elements
One constant pressure per element (mean dilatation, Nagtegaal, Parks &
Rice 1974; the hoop strain in the divergence) for quad4, quad8 and tri6:
the linear stiffness, stresses and thermal load, and the finite- and
small-strain forms of nonlinear steps with their consistent tangent. The
linear triangle and plane stress are refused by name.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 16:30:44 -04:00
jyvikoandClaude Opus 5.5 2ca5f84113 model: exterior edges of 2D elements
The boundary of a 2D model, which general contact takes by default.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 16:30:44 -04:00
jyvikoandClaude Opus 5.5 6da3055a1c fem: mortar integration over the edges of 2D models
Segment-to-segment overlap of two edges projected along the secondary
normal (Yang, Laursen & Meng 2005), three-point Gauss-Legendre with the
out-of-plane measure (thickness or 2 pi r) in the weight, over the same
Real scalars as faces so the solver gets exact derivatives.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 16:30:44 -04:00
jyvikoandClaude Opus 5.5 6bd52c0b29 engine: crank-arm sample, a bicycle crank swept all-hex and solved
file.sample crank-arm: a 170 mm 6061-T6 crank built in SolidCraft
(crates/engine/samples/crank-arm.json), swept along z by mesh.hex.generate
as 7274 hex20 elements of 3 mm (scaled Jacobian min 0.17). The hex variant
drops the pocket floor fillet and boss chamfers, and its root arcs meet the
bosses 20 degrees off tangent so the arm's top face has no zero-angle cusp.
The square bore is fixed and 1500 N acts on the pedal hole; the faces are
picked by their surfaces, not their names. Its heavy test matches the root
bending stress to M/Z = 62.6 MPa within 3 % (0.3 % in practice).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 16:20:35 -04:00
jyvikoandClaude Opus 5.5 98d263ae54 docs: examples gallery in the README
An Examples section before Build: a tile per sample with its picture, one
line and its name for File > Samples or fieldcraft --sample NAME, linking
docs/examples.md; the roadmap notes the gallery.

Closes #167

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:55:22 -04:00
jyvikoandClaude Opus 5.5 0b7f3021d9 engine: bracket-hex sample, the partitioned bracket meshed all-hex and solved
file.sample bracket-hex: the corpus bracket split into 30 SolidCraft cells,
meshed by mesh.hex.blocks as one conforming hex20 mesh of 3 mm, clamped at
the upright and loaded at the foot. The sample's script finds the clamp and
load faces in every cell that has them. Its test matches the tip deflection
of a fine tet10 solution within 1 % and checks the clamp carries the load.

Closes #166

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:55:22 -04:00
jyvikoandClaude Opus 5.5 f5a0a1289a engine: heated-bracket sample, steady heat and thermal stress in steel
file.sample heated-bracket: the corpus filleted bracket in steel, tet10, its
hole bores clamped, the upright's end held at 120 C and the rest cooled by
still air; one coupled temperature-displacement step. Its test checks the
temperatures against the heater and the air, then warms the bracket evenly,
clamps one hole, and matches the free thermal expansion alpha dT times the
distance from the hole along x.

Closes #165

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:55:22 -04:00
jyvikoandClaude Opus 5.5 ecdff11e72 engine: flow-past sample, air past an L-bracket on the floor
file.sample flow-past: air at 25 mm/s past the upright L-bracket in a box of
2.5 mm lattice cells (Re 83), inlet, outlet, a no-slip floor and slip walls;
the fluid step reports the force on each named face. Its test holds the
drag coefficient on the upright's frontal area between 1 and 3.5 (2.3) and
the lattice's mass change under 1 %. No picture: the viewport does not draw
flow results yet (M12).

Part of #164 (its streamlines wait for a flow display in the viewport)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:55:22 -04:00
jyvikoandClaude Opus 5.5 cf8ed71e4f engine: rubber-seal sample, a Mooney-Rivlin gasket ring squeezed 25 %
file.sample rubber-seal: a gasket ring of hybrid hex8 elements in four
mapped quarter blocks, squeezed 2.5 mm between plates bonded to it
(nonlinear static, Mooney-Rivlin rubber). Its test frees the plates and
matches the closed form for incompressible uniaxial compression within 3 %,
and bounds the bonded ring's extra stiffness. The plates are prescribed
displacements until implicit contact (#161) can press it into a groove.

Closes #163

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:55:22 -04:00
jyvikoandClaude Opus 5.5 581646bdac engine: drop-test sample, an aluminium bracket dropped onto a tilted floor
file.sample drop-test: an L-bracket standing on its foot (a SolidCraft script
in sample.rs) swept into hex8, falling 2 m onto a rigid floor tilted 15 deg;
explicit dynamics for 1 ms with gravity and plasticity. Its test checks the
mass against rho V, the impact speed sqrt(2 g h) and kinetic energy, the
energy balance and the momentum the floor takes. docs/examples.md starts
with it, and its picture is docs/media/examples/drop-test.png.

Closes #162

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:55:22 -04:00
jyvikoandClaude Opus 5.5 c9a765aa02 engine: samples can build their geometry from a SolidCraft script
A sample may carry a SolidCraft script (the corpus recipe form) whose design
opens before its commands run, and its script sees the design's bodies.
fieldcraft-engine now builds fieldcraft-geometry with its scripts feature.
The start screen scrolls its sample list, and a test keeps the file.sample
form's choices in step with the samples.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:55:22 -04:00
jyvikoandClaude Opus 5.5 0220e2d8bb engine, docs: self-contact in nonlinear static steps
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:47:17 -04:00
jyvikoandClaude Opus 5.5 85f0905db1 solver: single-surface (self) contact in nonlinear static steps
General contact, on a set's faces or every exterior face of the solids, is mortar contact
with one face list as both sides: each face against every other one that faces it, shares no
node with its element and is not reached through more than half an element, paired both
ways. Tested by a nearly incompressible Mooney-Rivlin C-ring (hybrid hex8) closing on itself
(no penetration beyond the mortar's weak enforcement, mirror symmetry to 1e-6) and, heavy, a
rubber bellows whose folds press on each other.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:47:17 -04:00
jyvikoandClaude Opus 5.5 2b1c52d021 verification: the tie patch test
An oracle case of uniaxial tension across a tie of non-matching meshes; the tie formulation
in docs/fem.md and the literature survey; ROADMAP M7 and parity updated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:28:02 -04:00
jyvikoandClaude Opus 5.5 794aa9f158 decks: ties as Abaqus *TIE and LS-DYNA tied contact
Nastran refuses them by name.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:28:02 -04:00
jyvikoandClaude Opus 5.5 7e9366f726 engine: interaction.tie, tie.edit and tie.delete
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:28:02 -04:00
jyvikoandClaude Opus 5.5 f9981d305e solver: ties by dual mortar constraints
Each secondary node follows the main surface under it as the weighted average
u_A = sum_J (M_AJ / sum_K M_AK) u_J with M_AJ = int psi_A N_J over the reference overlaps and
psi the secondary faces' dual shape functions (Wohlmuth 2000), so the secondary mortar
matrix is diagonal; the rows join the couplings' constraint elimination in every implicit
analysis. Uncovered secondary nodes stay free with a warning; heat transfer and explicit
dynamics refuse ties by name. Tested by the tie patch test on non-matching hex8/tet4 meshes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:28:02 -04:00
jyvikoandClaude Opus 5.5 8d2fa980a5 model: ties between surfaces
A tie names a main and a secondary face set and an optional position tolerance; it refers to
its sets, round-trips, is bounded in number and checked for solid faces.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:28:02 -04:00
jyvikoandClaude Opus 5.5 a91ac5baf9 verification: Coulomb friction between sliding blocks
An oracle case of a block pressed on another and slid with static and kinetic coefficients
(mu_k N carried once slipping), and the docs of the friction formulation; ROADMAP M7 and
parity updated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:14:14 -04:00
jyvikoandClaude Opus 5.5 32c5c1b307 engine: friction output of implicit contact
solve.nonlinear counts the slipping nodes, solve.probe gives a secondary node's shear traction
and slip, and the results display draws contact_shear and contact_slip, contact_status coding
stick and slip.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:14:14 -04:00
jyvikoandClaude Opus 5.5 6ca3233aaa solver: Coulomb friction for implicit mortar contact
A return map at the closed secondary nodes on the mortar slip in its rate form (w_A = B_A dx,
B_A = [int Phi_A N_i P, -int Phi_A N_j P]): stick within mu p_A, slip back to the cone, static
coefficient for a node that stuck in the last increment and kinetic for one that slipped; the
friction does the virtual work t . B_A dx, so a slipping interface carries mu N exactly. The
tangent is symmetrised (stick and slip stiffness kept, the coupling to the pressure and the
change of B left out; the residual is exact). Tractions and slip states are committed with the
converged increment. After a chattering cutback, nodes open by less than 1e-3 of their
element's thickness keep their penalty in the tangent for the rest of the step. Results carry
the shear traction, the slip and stick/slip status.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 15:14:14 -04:00
jyvikoandClaude Opus 5.5 945a2076c3 verification: implicit contact patch test and Hertz line contact
Two oracle cases: the contact patch test on non-matching meshes in small and finite sliding,
and Hertz's cylinder on a flat under force control (peak pressure, pressure distribution,
subsurface stress). docs/fem.md describes the formulation, the literature survey its papers;
ROADMAP M7 and parity are updated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 14:58:32 -04:00
jyvikoandClaude Opus 5.5 5770288f47 engine: contact output of nonlinear static steps
solve.nonlinear summarises each contact (normal force, largest pressure, closed nodes, deepest
penetration, augmentations), solve.probe gives a secondary node's pressure, gap and status per
contact, and the results display draws contact_pressure, contact_gap and contact_status. The
contact commands, the catalogue and the model docs say what nonlinear static steps do with a
pair.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 14:58:32 -04:00
jyvikoandClaude Opus 5.5 8871f6721d solver: mortar contact in nonlinear static steps
Frictionless contact pairs enforced by an augmented Lagrangian: nodal pressures from the
mortar weighted gaps, Uzawa updates after each converged increment until the gaps are within
1e-5 of the element thickness, and the consistent tangent (outer products of the weighted
gap gradients and the pressure-weighted Hessians from the automatic differentiation of the
mortar integrals). Finite sliding searches and integrates on the current configuration every
evaluation; without nonlinear geometry the pairs and their mortar integrals are fixed in the
reference configuration (small sliding, linear and exact). The tangent's pattern takes the
face pairs' blocks; the step cuts back when the active set chatters. Initial overclosure is
offset or refused; general contact, 2D models and arc length are refused by name; the linear
analyses refuse contact by name instead of the mesh.

With contact the convergence force scale comes from the converged states, the loads and the
current state. The loads-and-reactions balance check takes the nodal reactions into its scale
(no spurious warning for a part squeezed between held faces).

Tests: the contact patch test on non-matching hex8/tet4 meshes (exact with small sliding,
to 1e-4 with finite sliding), Hertz cylinder on a flat (peak pressure within 3%, half-width
bracketed) with quadratic Newton convergence, overclosure, thread-count determinism and the
refusals; Hertz sphere on a flat (heavy).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 14:58:32 -04:00
jyvikoandClaude Opus 5.5 37f338c9e8 fem: mortar segmentation of face pairs with forward-mode automatic differentiation
The overlap of a secondary face with a main face (projection onto the secondary plane,
Sutherland-Hodgman clipping of their triangles, Radon's seven-point rule on the overlap's
fan) and the inverse linear and bilinear maps of both faces, written over a Real scalar so
that f64, Dual (gradient) and Hyper (gradient and packed Hessian, 24 variables) give the
values and the exact linearisation of the segmentation, the normal and the projection.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 14:58:32 -04:00
jyvikoandClaude Opus 5.5 e8b0831884 release: version 0.5.7
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
v0.5.7
2026-10-14 14:30:47 -04:00
jyvikoandClaude Opus 5.5 bc75fd08d1 explicit: opt-in mass scaling to a target increment, the added mass reported
An explicit step may ask for mass scaling to a target time increment (on
a set, or the whole model): elements whose stable increment is below it
get the density that reaches it, with their lumped masses, frequency
bound and hourglass scales; adiabatic heating keeps the physical
density. The run reports the elements scaled, the added mass in all and
per section with its fraction, a warning, and the added mass's kinetic
energy in the energy account. Verified on a uniform bar scaled to twice
its increment (added mass 3×, increment doubled, a quarter of the
kinetic energy left to the physical mass). ROADMAP and parity note the
hyperelastic materials and mass scaling.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 14:29:43 -04:00
jyvikoandClaude Opus 5.5 ce8e23d05b explicit: hyperelastic materials on the shared finite-strain material point
Neo-Hookean, Mooney–Rivlin and Yeoh materials in explicit dynamics, in
total form from the deformation gradient (objective by construction):
the one-point hex8 takes its mean F over the undeformed element and the
stress τ/J; tet4 takes the isochoric stress of its own F with the
average nodal pressure of the decoupled volumetric energy (Bonet–Burton
at finite strain). Each element's frequency bound follows the tangent's
largest normal stiffness. Small-displacement steps and thermal strain of
hyperelastic elements are refused by name.

Verified by uniaxial strain to λ = 1.5 of all three laws on hex8 and
tet4 against the material point (to rounding), and the oracle case
explicit-neo-hookean-implicit: a quasi-static explicit pull against the
implicit nonlinear solver (lateral contraction to 0.09%, stress to 0.03%).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 14:29:43 -04:00
jyvikoandClaude Opus 5.5 94f7e8533a Revert the Abaqus comparison until its sources are confirmed public
Its values come from abaqus-docs.mit.edu, which returns 403 Forbidden outside MIT's network, so
they are not from a publicly accessible source. The section is kept aside for review.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 14:13:15 -04:00
jyvikoandClaude Opus 5.5 ebf8c655ee docs: compare FieldCraft's benchmark results with Abaqus's published values
A README section tabulates, per benchmark, the reference, the result the
Abaqus 2017 Benchmarks Guide publishes (element, mesh, error) and ours from
the oracle, with a cited source per value and notes where the rows are not
like for like. Linked from docs/verification.md.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 14:12:19 -04:00
jyvikoandClaude Opus 5.5 9f6afe7a89 verification: snap-through of a shallow arch by arc length
arc-shallow-arch: a sinusoidal arch of 40 × 2 × 1 hex20 under a sinusoidal dead load scaled to
the one-mode closed form's upper limit load: the upper limit point at 0.992 (−0.8 %), the lower
at 0.219 (0.8 % of the peak load) and exactly one negative eigenvalue between them. ROADMAP and
parity updated, docs/oracle.md regenerated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 13:53:27 -04:00
jyvikoandClaude Opus 5.5 a953dc6216 solver, model: arc-length control with critical points from the inertia
NonlinearStatic.arc_length {constraint, max_load_factor, displacement_limit}: Riks–Crisfield
arc-length increments (cylindrical or spherical arc, tangent predictor signed by the angle
criterion, the constraint's quadratic root chosen by the angle with the last iterate), arcs
grown, shrunk and cut back as increments are. The converged state's tangent is factored for the
next predictor (LDLᵀ when indefinite); its negative eigenvalues are recorded per increment and
changes in their count are reported as limit or bifurcation points. Ends at the maximum load
factor, a displacement limit or the increment cap. Abaqus *STATIC, RIKS; LS-DYNA refuses it by
name; forms gain the arc-length group. A shallow arch of hex20 snaps through on the closed-form
path (1.9 %), both limit points found, inertia 0 → 1 → 0 between them.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 13:53:27 -04:00
jyvikoandClaude Opus 5.5 72696614c2 engine: parameter schemas for solve.buckle, buckling steps and imperfections
Fixes the build of develop: #171 crossed with the typed command forms, so BUCKLE lacked its
form. SOLVE_BUCKLE follows SOLVE_FREQUENCY; the step form gains the buckle variant and the
nonlinear step's imperfection group.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 13:41:29 -04:00
jyvikoandClaude Opus 5.5 0bb1c2462f solver, model: imperfections from buckling modes in nonlinear steps
NonlinearStatic.imperfection {step, mode, scale}: the buckling step's mode, scaled to a largest
component of `scale`, is added to the node coordinates before the step is solved, with a warning
naming it; Abaqus and LS-DYNA decks refuse it by name. A clamped–free column with its first mode
as imperfection under half its buckling load amplifies it by 1/(1 − α) within 2.8 %.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 13:30:59 -04:00
jyvikoandClaude Opus 5.5 788edbbddd verification: Euler columns and Bryan's plate in buckling steps
buckle-euler-pinned and buckle-euler-cantilever (hex20 columns, −0.18 % from Euler with
Engesser's shear correction) and buckle-plate-square (a simply supported square plate, b/t =
100, −0.39 % from k = 4; the support and thickness choices in its README). ROADMAP and parity
updated, docs/oracle.md regenerated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 13:30:59 -04:00
jyvikoandClaude Opus 5.5 1b57e2e672 solver, model, engine: linear buckling steps
Procedure::Buckle {modes, shift}: the step's loads as a linear preload, K_σ from its stresses,
and (K + λ K_σ) φ = 0 by block Lanczos in the K inner product: K⁻¹(−K_σ) on Cholesky without a
shift, the buckling transformation (K + σ K_σ)⁻¹ K on LDLᵀ with one, whose inertia counts the
load factors below σ (Grimes–Lewis–Simon 1994). Lanczos gains an operand and an eigenvalue map
(defaults keep frequency steps bit for bit) and reports converged negative eigenvalues. Results
are frequency results with a `buckling` part; modes display with their load factor.
solve.buckle (in the Static drop-down); Abaqus *BUCKLE, Nastran SOL 105 and LS-DYNA refuse it by
name. Euler columns of hex20 within 0.18 % of Engesser's load.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 13:30:59 -04:00
jyvikoandClaude Opus 5.5 9a8ae50bca fem: initial-stress (geometric) stiffness of solid and 2D elements
K_σ = ∫ (∇N_a · σ ∇N_b) I dV for a stress state at the stiffness points (solids, plane and
axisymmetric elements with the hoop term), for linear buckling. Checked: uᵀK_σu = σ V for a
uniform stress on a distorted hex20 and a plane strain quad8, rigid translations in its null space.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-14 13:30:59 -04:00
jyvikoandClaude Opus 5.5 188f2d5fc4 mcp, cli: list each command's parameters as JSON Schema
CommandSpec::listing gives id, label, the parameter doc and the schema; MCP
list_commands, the control channel's engine.commands and the new
fieldcraft-cli commands --json use it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 13:20:04 -04:00
jyvikoandClaude Opus 5.5 217628ead4 ui: command forms drawn from the parameter schema
The context panel's form shows typed fields instead of the JSON text: numbers
with the model's units, drop-downs of choices and of the model's sets,
materials, steps and bodies, checkboxes, vectors, groups and one-of variants
(a load's type switches its fields), lists of rows. Defaults are filled in,
required fields are marked, a value the schema finds wrong is noted under its
field, and OK waits while a field holds text that is not a value. The JSON
text stays as the Advanced view. fields.rs holds the generic widgets (row,
number, drop-down, text), adapted from SolidCraft's dialog rows.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 13:20:04 -04:00
jyvikoandClaude Opus 5.5 8848ef9e7c engine: parameter schemas for every command
cmd/forms.rs describes each command's parameters: model definitions (sets,
materials with elasticity, plasticity, hyperelasticity, damage, thermal and fluid
options, sections, reference points, couplings, masses, springs, boundary
conditions, loads, fluid domains, steps including nonlinear and explicit),
meshers, solvers, deck export, files and results. Tests check that every command
has a form and that a form's defaults are accepted or refused only for the
required fields left empty.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 13:20:04 -04:00
jyvikoandClaude Opus 5.5 5c5516aae0 engine: a typed parameter schema per command (CommandSpec::form)
Field, Kind, Dim and Collection describe a command's JSON parameters: numbers with
unit dimensions, choices, vectors, references to model items, groups, one-of
variants and rows. prefill, switch_variant and problems serve forms; json_schema
gives the same as JSON Schema. No command is described yet (form: None).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-14 13:20:04 -04:00
jyvikoandClaude Opus 5.5 6a604c24b6 release: version 0.5.6
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo
2026-10-14 12:52:15 -04:00
jyvikoandClaude Opus 5.5 a30d0b5c5b explicit: deformable contact and friction, verified by bars, sliding blocks, the patch test and Hertz
Segment-to-segment penalty contact between element faces: each secondary
face and each main face facing it are projected onto the secondary face's
plane, split into triangles, clipped (Sutherland–Hodgman) and integrated
with a three-point rule per sub-triangle (Puso–Laursen segmentation, the
penalty at the integration points as Fischer–Wriggers), so a uniform
pressure gives the consistent nodal forces on both meshes and the contact
patch test passes on non-matching meshes. Every contact runs both ways at
half the penalty: pairs with each surface as the secondary, general and
self contact face against face. A bucket grid of face boxes every
increment, faces integrated in parallel and their forces added in face
order: the same numbers on any thread count.

The penalty per area ε = s γ min(m/A)/Δt² comes from the lumped masses,
each node's directional area and the stable increment, bounded by
Gershgorin's row sums so contact never shortens the increment. Coulomb
friction with exponential decay by a regularised return map at the
secondary nodes; rigid walls take Coulomb impulses. Contact work and
friction dissipation join the energy balance; each contact reports its
peak force, first and last contact, deepest penetration, friction and the
nodes adjusted at the start (initial penetrations adjusted strain-free or
refused with the node, face and depth); a cap on contact faces.

Verified (crates/explicit/tests/contact.rs, tests/oracle/explicit-*):
colliding bars (2L/c +1.2%, ρcAv₀/2, KE kept to 0.005%, contact energy
back to 8e-5 of it), blocks sliding to a stop on a rigid wall and on a
plate under constant and decaying friction (0.005–0.2%), the patch test
(σ_zz uniform to 0.06%), two spheres colliding against Hertz (peak +2.3%,
duration −0.4%; the oracle case waits for a graded sphere mesher), a free
body untouched by general contact, determinism across threads. Oracle
measures gain `over` (ratios). Existing fixtures do not move.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm
2026-10-14 12:49:45 -04:00
jyvikoandClaude Opus 5.5 ecf947c090 model: contact pairs, general contact and Coulomb friction, mapped by the deck writers
Contact definitions on face sets: a pair (each surface's nodes against the
other's faces), general contact on a surface (self contact) or on every
exterior face of the solids; Coulomb friction with static and kinetic
coefficients and an exponential decay, a penalty scale and the choice to
adjust or refuse initially penetrating nodes, validated with caps. Rigid
walls of explicit steps gain friction. The check wants solid faces on
contact surfaces; sets used by a contact cannot be deleted.

fem::contact: the closest point of a triangle (Ericson) or a bilinear
quadrilateral (projected Newton) to a point, and a bucket grid of face
boxes for the global search, deterministic and bounded.

Commands interaction.contact.pair, .general, .edit, .delete and .find
(the touching parts of the mesh, with face sets and pairs made of them);
contacts in the model browser. Abaqus writes *SURFACE INTERACTION with
*FRICTION (exponential decay), *CONTACT PAIR and general *CONTACT; LS-DYNA
*CONTACT_AUTOMATIC_SURFACE_TO_SURFACE and _SINGLE_SURFACE with FS, FD, DC;
Nastran refuses contact by name. The implicit solver refuses contact by
name (M7); the explicit solver refuses it until the next commit.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm
2026-10-14 12:49:45 -04:00