{
  "tool": "Joint Stress Calculator",
  "owner": "Albert Karaca",
  "domain": "Douglas Fir-Larch mortise-and-tenon joinery",
  "purpose": "Audit tenon thickness, shear area, and bending stress before cutting a joint",
  "reference": {
    "authority": "NDS 2018, Table 4A",
    "caveat": "Reference design values; apply adjustment factors (CD, wet service, temperature, member size) per governing NDS conditions for final allowable capacity",
    "field_rule": "Tenon thickness = stile thickness / 3; verify against woodshop experience, not the other way round"
  },
  "constants": {
    "Douglas_Fir-Larch_Select_Structural": {"Fb_psi": 1750, "Fv_psi": 180},
    "Douglas_Fir-Larch_No1": {"Fb_psi": 1350, "Fv_psi": 180},
    "Douglas_Fir-Larch_No2": {"Fb_psi": 1000, "Fv_psi": 180}
  },
  "formulas": {
    "tenon_thickness_in": "stile_thickness / 3",
    "shear_area_in2": "tenon_thickness * tenon_width",
    "actual_shear_psi": "applied_load / shear_area",
    "bending_moment_lbfin": "applied_load * tenon_length",
    "section_modulus_in3": "tenon_thickness * tenon_width^2 / 6",
    "actual_bending_psi": "bending_moment / section_modulus",
    "pass": "actual_shear <= Fv AND actual_bending <= Fb"
  },
  "worked_example": {
    "stile_thickness_in": 1.5,
    "tenon_width_in": 4,
    "tenon_length_in": 2,
    "applied_load_lbf": 600,
    "grade": "Douglas_Fir-Larch_No1",
    "tenon_thickness_in": 0.5,
    "shear_area_in2": 2.0,
    "actual_shear_psi": 300,
    "actual_bending_psi": 300,
    "result": "SHEAR FAIL — 300 psi exceeds Fv 180 psi; widen/deepen the tenon or increase thickness"
  },
  "url": "https://albert-karaca.4ort.net/joint-stress-tool/",
  "related": [
    "https://albert-karaca.4ort.net/precision-in-gaming-operations.html",
    "https://albert-karaca.4ort.net/variance-protocol.html"
  ]
}