oracle: 2D cases (Kirsch plane stress, Lamé plane strain and axisymmetric, rotating disc and cylinder, NAFEMS LE1 with quad8) and J2 uniaxial explicit

The pending 2D LE1 case becomes a real one; the plasticity cases stay
pending with what they still need (static J2 for the collapse pressure,
the transcribed measurements for the Taylor bar).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

tests/oracle/kirsch-plate-plane-stress/README.md

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+# Plate with a circular hole in tension, 2D plane stress (Kirsch)
+
+The plate of `kirsch-plate` as a 2D plane stress model: a quarter of half-width 30 with a hole of
+radius 1, two quad8 patches around the hole (40 × 16 each, graded 40 : 1 towards it, mid-side
+nodes on the arc), symmetry on x = 0 and y = 0, a traction of 1 on x = 30.

tests/oracle/kirsch-plate-plane-stress/expected.json

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+{
+ "title": "Plate with a circular hole in tension, 2D plane stress (Kirsch)",
+ "kind": "theory",
+ "source": "Kirsch, Zeitschrift des VDI 42 (1898) 797–807; Timoshenko and Goodier, Theory of Elasticity, 3rd ed., 1970, §35",
+ "quantities": [
+  {
+   "id": "kt",
+   "quantity": "σ_xx at the top of the hole (0, 1) over the remote stress",
+   "measure": {
+    "command": "solve.probe",
+    "params": {
+     "step": "Tension",
+     "at": [
+      [
+       0,
+       1.0,
+       0
+      ]
+     ]
+    },
+    "pointer": "/nodes/0/stress/0"
+   },
+   "value": 3.0,
+   "tolerance": {
+    "relative": 0.02
+   },
+   "reason": "the reference is the infinite plate; the finite plate (W = 60a, loaded ends 30a away) raises the peak by a few tenths of a percent, and the stress extrapolated to the hole surface adds up to about 1%"
+  },
+  {
+   "id": "side",
+   "quantity": "σ_yy at the side of the hole (1, 0) over the remote stress",
+   "measure": {
+    "command": "solve.probe",
+    "params": {
+     "step": "Tension",
+     "at": [
+      [
+       1.0,
+       0,
+       0
+      ]
+     ]
+    },
+    "pointer": "/nodes/0/stress/1"
+   },
+   "value": -1.0,
+   "tolerance": {
+    "relative": 0.03
+   },
+   "reason": "infinite-plate value −S; finite width and extrapolation as for Kt, on a smaller value"
+  }
+ ]
+}

tests/oracle/kirsch-plate-plane-stress/fixture.json

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+{
+  "note": "ModelCraft's accepted results for this case, written by `cargo xtask oracle --bless`. A result outside its band fails CI.",
+  "values": {
+    "kt": {
+      "band": 3.0028789592374985e-9,
+      "value": 3.0028789592374983
+    },
+    "side": {
+      "band": 1.0018737796236792e-9,
+      "value": -1.0018737796236792
+    }
+  }
+}

tests/oracle/kirsch-plate-plane-stress/recipe.json

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+[
+ {"command": "mesh.block", "params": {"body": "Plate", "kind": "quad8", "corners": [[1.0, 0, 0], [30.0, 0, 0], [30.0, 30.0, 0], [0.7071067811865476, 0.7071067811865476, 0]], "divisions": [40, 16], "bias": [40, 1], "edges": [{"corners": [1, 4], "arc": {"center": [0, 0, 0]}}, {"corners": [1, 2], "name": "y0"}, {"corners": [2, 3], "name": "load"}]}},
+ {"command": "mesh.block", "params": {"body": "Plate", "kind": "quad8", "corners": [[0.7071067811865476, 0.7071067811865476, 0], [30.0, 30.0, 0], [0, 30.0, 0], [0, 1.0, 0]], "divisions": [40, 16], "bias": [40, 1], "edges": [{"corners": [1, 4], "arc": {"center": [0, 0, 0]}}, {"corners": [3, 4], "name": "x0"}]}},
+ {"command": "model.set.create", "params": {"name": "all", "geometry": [{"body": "Plate", "face": "area"}]}},
+ {"command": "model.set.create", "params": {"name": "x0", "geometry": [{"body": "Plate", "edge": "x0"}]}},
+ {"command": "model.set.create", "params": {"name": "y0", "geometry": [{"body": "Plate", "edge": "y0"}]}},
+ {"command": "model.set.create", "params": {"name": "load", "geometry": [{"body": "Plate", "edge": "load"}]}},
+ {"command": "model.material.create", "params": {"name": "Mat", "elastic": {"type": "isotropic", "young": 1000.0, "poisson": 0.3}}},
+ {"command": "model.section.create", "params": {"name": "plate", "set": "all", "material": "Mat", "kind": {"type": "plane_stress", "thickness": 0.1}}},
+ {"command": "model.boundary_condition.create", "params": {"name": "sx", "type": "symmetry", "target": {"set": "x0"}, "plane": "x"}},
+ {"command": "model.boundary_condition.create", "params": {"name": "sy", "type": "symmetry", "target": {"set": "y0"}, "plane": "y"}},
+ {"command": "model.load.create", "params": {"name": "S", "type": "traction", "set": "load", "vector": [1, 0, 0]}},
+ {"command": "model.step.create", "params": {"name": "Tension", "procedure": {"type": "static"}, "boundary_conditions": ["sx", "sy"], "loads": ["S"]}},
+ {"command": "solve.static", "params": {}, "id": "solve"}
+]