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