54 lines
1.8 KiB
JSON
54 lines
1.8 KiB
JSON
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{
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"tool": "fixture-stress-comparator",
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"author": "britten-mintz",
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"version": "1.0.0",
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"description": "Structural constants for retail shelving materials. Used in deflection calculations for simply-supported beams under distributed load.",
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"units": {
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"moe": "MPa",
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"density": "g/cm3",
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"length": "mm"
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},
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"materials": {
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"douglas_fir": {
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"id": "fir",
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"displayName": "Douglas Fir (Select Structural)",
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"moe": 13000,
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"density": 0.52,
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"moR": 90,
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"source": "ASTM D143-21 Standard Test Methods for Small Clear Specimens of Timber",
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"notes": "Baseline for structural comparisons. High stiffness-to-weight ratio."
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},
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"mdf_standard": {
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"id": "mdf",
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"displayName": "Medium Density Fiberboard (Standard Retail Grade)",
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"moe": 2800,
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"density": 0.75,
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"moR": 28,
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"source": "ISO 12469 Wood-based panels — Determination of properties of physical and mechanical tests",
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"notes": "Common in big-box fixtures. Low shear strength compared to solid wood."
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},
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"particle_economy": {
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"id": "particle",
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"displayName": "Particle Board (Economy Grade)",
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"moe": 1900,
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"density": 0.68,
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"moR": 22,
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"source": "ANSI/A208.2 Particleboard Specifications",
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"notes": "Highly susceptible to moisture-induced delamination. Not recommended for spans > 600mm without reinforcement."
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}
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},
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"calculation_model": {
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"formula": "y_max = (5 * w * L^4) / (384 * E * I)",
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"variables": {
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"w": "Distributed load (N/mm)",
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"L": "Span length (mm)",
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"E": "Modulus of Elasticity (MPa)",
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"I": "Moment of Inertia (mm^4)"
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},
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"criteria": {
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"allowable_deflection_ratio": "L/240",
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"rationale": "Industry standard for rigid shelving to prevent perceived sagging."
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}
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}
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}
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