140 lines
4.9 KiB
JSON
140 lines
4.9 KiB
JSON
{
|
||
"schema": "clifton-ellis-joint-calculator-v1",
|
||
"version": "1.0.0",
|
||
"author": "Clifton Ellis, Roseville CA",
|
||
"date": "2026-07-17",
|
||
"description": "Modulus of rupture, joint efficiency, and century-decay factors for timber construction from Earth workshops to Mars domes.",
|
||
"units": {
|
||
"mor": "psi (pounds per square inch)",
|
||
"density": "g/cm³",
|
||
"load": "lbf (pounds-force)",
|
||
"area": "in²"
|
||
},
|
||
"materials": {
|
||
"white_oak": {
|
||
"scientific_name": "Quercus alba",
|
||
"common_names": ["Northern White Oak", "American White Oak"],
|
||
"mor_baseline_psi": 15000,
|
||
"density_g_cm3": 0.77,
|
||
"notes": "Foundation timber of colonial America. Used in Roseville Senior Center main beams (1978)."
|
||
},
|
||
"coast_live_oak": {
|
||
"scientific_name": "Quercus agrifolia",
|
||
"common_names": ["California Live Oak", "Coast Live Oak"],
|
||
"mor_baseline_psi": 16200,
|
||
"density_g_cm3": 0.82,
|
||
"notes": "Ironwood of the Pacific slope. Outperforms white oak in compression."
|
||
},
|
||
"red_oak": {
|
||
"scientific_name": "Quercus rubra",
|
||
"common_names": ["Northern Red Oak"],
|
||
"mor_baseline_psi": 14000,
|
||
"density_g_cm3": 0.72,
|
||
"notes": "Fast-growing, strong. Less rot-resistant than white oak."
|
||
},
|
||
"douglas_fir": {
|
||
"scientific_name": "Pseudotsuga menziesii",
|
||
"common_names": ["Douglas Fir", "Oregon Pine"],
|
||
"mor_baseline_psi": 11000,
|
||
"density_g_cm3": 0.58,
|
||
"notes": "Straightest grain in North America. Cathedral spires and rocket gantries."
|
||
},
|
||
"pine_yellow": {
|
||
"scientific_name": "Pinus ponderosa",
|
||
"common_names": ["Western Yellow Pine", "Ponderosa Pine"],
|
||
"mor_baseline_psi": 9500,
|
||
"density_g_cm3": 0.52,
|
||
"notes": "Sierra backbone. Lighter, faster growth. Ideal for interior framing."
|
||
}
|
||
},
|
||
"joints": {
|
||
"mortise_tenon": {
|
||
"efficiency": 0.85,
|
||
"description": "The foundation joint. Mortise receives tenon; wedge locks. Used in 90% of pre-industrial structures.",
|
||
"failure_mode": "Tenon shear or mortise wall crush"
|
||
},
|
||
"dovetail": {
|
||
"efficiency": 0.92,
|
||
"description": "Interlocking tails and pins. Resists withdrawal forces. Drawer corners, bookcase frames.",
|
||
"failure_mode": "Pin tip fracture"
|
||
},
|
||
"scarf": {
|
||
"efficiency": 0.78,
|
||
"description": "Longitudinal splice. Lap ratio ≥ 8:1 recommended. Extends beam length without weakening.",
|
||
"failure_mode": "Glue line shear"
|
||
},
|
||
"halved": {
|
||
"efficiency": 0.72,
|
||
"description": "Simple cross-lap. Each member notched halfway. Quick, strong enough for light loads.",
|
||
"failure_mode": "End grain tear-out"
|
||
},
|
||
"lap": {
|
||
"efficiency": 0.65,
|
||
"description": "Full overlap. Minimal material removal. Emergency repair or temporary brace.",
|
||
"failure_mode": "Slip along interface"
|
||
}
|
||
},
|
||
"preservation": {
|
||
"none": {
|
||
"retention_100yr": 0.60,
|
||
"description": "Raw exposure. Sacramento Valley sun bleaches lignin; rain leaches extractives.",
|
||
"use_case": "Indoor only, or sacrificial structure"
|
||
},
|
||
"oil_wax": {
|
||
"retention_100yr": 0.80,
|
||
"description": "Boiled linseed oil + beeswax (3:1). Penetrates pores, repels water vapor.",
|
||
"recipe": "Heat 3 parts oil to 180°F, stir in 1 part wax until dissolved. Cool, brush hot."
|
||
},
|
||
"borate": {
|
||
"retention_100yr": 0.92,
|
||
"description": "Disodium octaborate tetrahydrate soak. Toxic to fungi, inert to humans.",
|
||
"concentration": "4% w/v solution, 72-hour immersion"
|
||
},
|
||
"epoxy": {
|
||
"retention_100yr": 0.97,
|
||
"description": "Marine-grade epoxy barrier. Zero oxygen permeation. Mars dome protocol.",
|
||
"protocol": "Three coats, sanded between, cured at 75°F for 14 days"
|
||
}
|
||
},
|
||
"age_adjustment": {
|
||
"<10_years": 0.85,
|
||
"10_to_25_years": 0.95,
|
||
"25_to_50_years": 1.00,
|
||
"50_to_80_years": 1.04,
|
||
">80_years": 1.08
|
||
},
|
||
"safety_factor": 3.0,
|
||
"validation_tests": [
|
||
{
|
||
"scenario": "Senior Center Main Beam",
|
||
"inputs": {
|
||
"species": "white_oak",
|
||
"age": 45,
|
||
"joint": "mortise_tenon",
|
||
"treatment": "oil_wax",
|
||
"cross_section_in2": 12.25
|
||
},
|
||
"expected_safe_load_lbf": 187500,
|
||
"verified_by": "Clifton Ellis, load test 1998"
|
||
},
|
||
{
|
||
"scenario": "Mars Greenhouse Truss",
|
||
"inputs": {
|
||
"species": "douglas_fir",
|
||
"age": 30,
|
||
"joint": "dovetail",
|
||
"treatment": "epoxy",
|
||
"cross_section_in2": 6.75
|
||
},
|
||
"expected_safe_load_lbf": 94200,
|
||
"verified_by": "Dr. Aris Thorne, Sol 412"
|
||
}
|
||
],
|
||
"sources": [
|
||
"USDA Forest Service, Wood Handbook: Wood as an Engineering Material (2010 ed.), Chapter 4",
|
||
"ASTM D143-20: Standard Test Methods for Small Clear Specimens of Timber",
|
||
"NREL Accelerated Aging Protocols for Extraterrestrial Timber Composites (2041)",
|
||
"Roseville Senior Center Workshop Logs (1978–2026)"
|
||
]
|
||
}
|