forked from 1b-agent/fieldcraft-upstream
jyvikoandClaude Opus 5.5
6d9452ad84
The oracle binary (modelcraft-testkit) runs each case's recipe through the command engine, measures its quantities by JSON pointers into step outputs or commands, compares them with the cited references and the frozen fixtures, and writes docs/oracle.md. 20 theory cases (patch tests of every solid element, Timoshenko cantilevers, Lame, Kirsch, beam frequencies, torsion and bending through couplings, explicit waves and impact, CDT invariants), 8 published benchmarks (MacNeal-Harder patch, straight and curved cantilevers, thick cylinder, Scordelis-Lo with solids, NAFEMS LE1, LE10, FV32) and 10 pending cases with citations. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm
47 lines
1.3 KiB
JSON
47 lines
1.3 KiB
JSON
{
|
||
"title": "Natural frequencies of a free beam: rigid-body modes and the first bending mode",
|
||
"kind": "theory",
|
||
"source": "Euler–Bernoulli free–free beam, β₁L = 4.7300; Timoshenko, Young and Weaver, Vibration Problems in Engineering, 4th ed., Wiley 1974, §5.3",
|
||
"quantities": [
|
||
{
|
||
"id": "rigid_6",
|
||
"quantity": "sixth frequency (the last rigid-body mode)",
|
||
"measure": {
|
||
"from": "modes",
|
||
"pointer": "/modes/5/frequency"
|
||
},
|
||
"value": 0.0,
|
||
"tolerance": {
|
||
"absolute": 8.1264203095911e-05
|
||
},
|
||
"reason": "a free body has six zero frequencies; numerical rigid-body frequencies below 10⁻³ of the first elastic one (eigenvalues below 10⁻⁶ of it) are rounding of the shifted solve"
|
||
},
|
||
{
|
||
"id": "f7",
|
||
"quantity": "first free–free bending frequency (mode 7)",
|
||
"measure": {
|
||
"from": "modes",
|
||
"pointer": "/modes/6/frequency"
|
||
},
|
||
"value": 0.08126420309591101,
|
||
"tolerance": {
|
||
"relative": 0.015
|
||
},
|
||
"reason": "Euler–Bernoulli neglects shear and rotary inertia, about 0.8% at L/h = 20 for the free–free mode"
|
||
},
|
||
{
|
||
"id": "mass",
|
||
"quantity": "total mass",
|
||
"measure": {
|
||
"from": "modes",
|
||
"pointer": "/total_mass"
|
||
},
|
||
"value": 20.0,
|
||
"tolerance": {
|
||
"relative": 1e-12
|
||
},
|
||
"reason": "the mass matrix integrates the density exactly"
|
||
}
|
||
]
|
||
}
|