Awatif linear frame solver API

POST https://awatif.co/api/solve
Content-Type: application/json
No API key. Free demo endpoint: linear static analysis of 3D frames.

Limits: at most 100 nodes and 200 elements per call, 1 MB body,
2-node frame elements only.

Units: any consistent set, returned as sent. Recommended: m, N, N·m, Pa.

Request body
{
  "nodes":         [[x, y, z], ...],                      // node i = index i
  "elements":      [[startNode, endNode], ...],           // element i = index i
  "supports":      [[node, [ux, uy, uz, rx, ry, rz]], ...], // true = restrained
  "loads":         [[node, [Fx, Fy, Fz, Mx, My, Mz]], ...],
  "elementsProps": [[element, { "elasticity", "area", "momentInertiaZ",
                                "momentInertiaY", "shearModulus",
                                "torsionalConstant" }], ...],  // one per element
  "releases":      [[element, [startMy, startMz, endMy, endMz]], ...]  // optional, true = moment released
}

Response 200
{
  "positions":      [x1, y1, z1, x2, y2, z2, ...],       // deformed node positions, flat
  "internalForces": [[element, { "N": [start, end], "Vy": [...], "Vz": [...],
                                 "Mx": [...], "My": [...], "Mz": [...] }], ...],
  "iterationCount": 1                                     // linear: always one solve
}
Section forces: N compression-positive; My and Mz sagging-negative, Vy and Vz
signed with them. Local axes follow the Awatif convention.

Errors: {"error": "..."} with 400 (invalid model), 413 (body too large),
422 (unstable model: check supports and releases), 405 (other methods).

Example: a 6 m simply supported beam, 1 kN/m lumped to the midspan node
curl -X POST https://awatif.co/api/solve -H 'Content-Type: application/json' -d '{
  "nodes": [[0,0,0],[3,0,0],[6,0,0]],
  "elements": [[0,1],[1,2]],
  "supports": [[0,[true,true,true,true,false,false]],[2,[false,true,true,false,false,false]]],
  "loads": [[1,[0,0,-3000,0,0,0]]],
  "elementsProps": [[0,{"elasticity":2.1e11,"area":0.00538,"momentInertiaZ":8.36e-5,"momentInertiaY":6.04e-6,"shearModulus":8.1e10,"torsionalConstant":2e-7}],
                    [1,{"elasticity":2.1e11,"area":0.00538,"momentInertiaZ":8.36e-5,"momentInertiaY":6.04e-6,"shearModulus":8.1e10,"torsionalConstant":2e-7}]]
}'