#structural

Reinforcement-steel (rebar) maths as an API, computed locally and deterministically. The area endpoint computes the cross-sectional area of a reinforcing bar, a = π/4·d², its mass per metre (a·7850/1e6, steel ρ = 7850 kg/m³), the total area and mass for a number of bars, and — given a required steel area — the number of bars needed and the area provided. The spacing endpoint lays out bars across a section: from the width, the cover, the bar diameter and either a centre-to-centre spacing or a bar count it returns the other, n = floor((width − 2·cover − d)/spacing) + 1, the total steel area and the area per metre of width. The ratio endpoint computes the reinforcement ratio ρ = As/(b·d) of a section from the steel area (or the bars) and the section width and effective depth, as a fraction and a percentage, the single number that governs whether a beam is under- or over-reinforced. Everything is computed locally and deterministically, so it is instant and private. Ideal for structural and site-engineering tools, reinforced-concrete detailing, bar-bending schedules and steel take-off, and civil-engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is rebar geometry and quantities; for concrete mix proportions use a concrete API.

api.oanor.com/rebar-api

Structural wind-load maths as an API, computed locally and deterministically. The pressure endpoint computes the velocity (dynamic) pressure of wind, q = ½·ρ·v², from the wind speed and air density — the pressure the wind exerts when it is brought to rest against a surface — and also solves the wind speed back from a given pressure, reporting the speed in m/s, km/h and mph. The force endpoint computes the wind force on a surface, F = q·Cf·A, from the velocity pressure (or wind speed), the exposed area and a force coefficient (≈1.3 for a building wall, ≈1.2 for a flat plate), and — given a height — the overturning moment about the base. The beaufort endpoint converts between a wind speed and the Beaufort scale using v = 0.836·B^1.5, returning the Beaufort number, the standard description from calm to hurricane force and the corresponding pressure. Everything is computed locally and deterministically, so it is instant and private. Ideal for structural and façade-engineering tools, signage, solar-array, scaffold and temporary-structure wind checks, sailing and meteorology apps, and engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is structural wind pressure and force; for wind-turbine energy output use a wind-power API.

api.oanor.com/windload-api

Euler column buckling as an API, computed locally and deterministically. The critical-load endpoint computes the Euler critical (buckling) load of a slender column, Pcr = π²·E·I / (K·L)², from the Young's modulus, the second moment of area, the length and the end conditions — pinned-pinned (K=1), fixed-fixed (K=0.5), fixed-pinned (K≈0.7) or fixed-free / cantilever (K=2), or a custom effective-length factor — and, given the cross-section area, also the radius of gyration, slenderness ratio and critical buckling stress. The section endpoint returns the area, the second moment of area about both axes and the radius of gyration for a solid circle, a hollow circle or tube, or a rectangle, and highlights the weak-axis value that governs buckling. The slenderness endpoint computes the slenderness ratio λ = K·L/r and, given the modulus and yield strength, the transition slenderness λ1 = π·√(2E/σy) that separates long Euler columns from short and intermediate ones, classifies the column and returns both the Euler and the J.B. Johnson critical stresses. Everything is computed locally and deterministically, so it is instant and private. Ideal for structural, mechanical and aerospace engineering tools, strut and frame design, machine-design and stability-analysis apps, and engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is column buckling and stability; for beam bending, shear and deflection use a beam-statics API.

api.oanor.com/buckling-api

Mohr's circle and 2D (plane) stress transformation as an API, computed locally and deterministically. The principal endpoint takes a plane-stress state — the normal stresses σx and σy and the shear stress τxy — and returns the principal stresses σ1 and σ2 = (σx+σy)/2 ± √(((σx−σy)/2)² + τxy²), the maximum in-plane shear stress, the orientation of the principal and maximum-shear planes, the centre and radius of Mohr's circle, and the von Mises and Tresca equivalent stresses (treating plane stress with the third principal σ3 = 0). The transform endpoint rotates the stress state onto a plane at any angle θ, returning σx', σy' and τx'y' using the standard transformation equations, and confirms the σx+σy invariant. The safety endpoint computes the factor of safety against a material's yield strength under either the von Mises (distortion-energy) or the Tresca (maximum-shear) criterion, from a full stress state or from principal stresses directly. Everything is computed locally and deterministically, so it is instant and private. Ideal for mechanical, structural and aerospace engineering tools, finite-element pre- and post-processing, machine-design and stress-analysis apps, and engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is stress-state analysis; for fillet-weld throat sizing use a weld API and for helical-spring rates use a spring API.

api.oanor.com/mohr-api

Weld design maths as an API, computed locally and deterministically. The fillet endpoint sizes an equal-leg fillet weld: from the leg size, the weld length and an allowable shear stress it returns the effective throat (leg ÷ √2), the effective area, the load capacity and the strength per millimetre of weld; give a design force instead of a leg and it returns the required throat and leg size, and if you also pass a provided leg it reports the utilization and whether the weld is adequate. The butt endpoint handles a full-penetration butt (groove) weld, where the effective throat equals the plate thickness, returning the area and capacity. The throat endpoint converts between leg and throat — equal-leg (throat = leg ÷ √2), unequal legs (throat = a·b ÷ √(a²+b²)) and throat back to leg. Lengths are in millimetres, stress in megapascals and force in newtons. Everything is computed locally and deterministically, so it is instant and private. An estimating aid, not a code-stamped design — use the allowable stress and electrode from your governing code (AISC, Eurocode). Ideal for structural and fabrication tools, weld-design and estimating apps, maker and metalwork projects, and engineering calculators. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is weld strength sizing; for bolt tightening torque use a torque API and for the weight of the steel use a metal-weight API.

api.oanor.com/weld-api

Roof snow-load maths as an API, computed locally and deterministically using the ASCE 7 method. The roof endpoint turns a ground snow load into the design roof snow load: the flat-roof load is pf = 0.7 · Ce · Ct · Is · pg, using the exposure, thermal and importance factors, and the sloped-roof load is ps = Cs · pf, where the slope factor Cs follows the warm-roof all-surfaces curve (1.0 up to 30°, falling linearly to 0 at 70°) or a value you supply. It reports every load in kilopascals, pascals, pounds per square foot and kilograms per square metre, and — if you give a roof area — the total load in kilonewtons, kilograms, tonnes and pounds. The depth endpoint converts a measured snow depth and a density (given directly or by snow type, from fresh ~100 to ice ~917 kg/m³) into a load. The convert endpoint converts a snow load between kPa, psf, kg/m², Pa and psi. Depths accept millimetres, centimetres, metres, inches or feet. Everything is computed locally and deterministically, so it is instant and private. An engineering aid, not a code-stamped design — always confirm against the governing local code with a qualified engineer. Ideal for structural and roofing tools, building-code and permitting apps, solar-install and carport planners, and winter-risk calculators. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is roof snow-load engineering; for roof pitch and area geometry use a roofing API and for beam reactions use a beam API.

api.oanor.com/snowload-api

Beam statics as an API, computed locally and deterministically. The simply-supported endpoint analyses a beam on two supports under a point load (anywhere along the span) or a uniformly distributed load: it returns the support reactions, the maximum shear and the maximum bending moment with its location, and — if you pass the Young's modulus E and second moment of area I — the maximum deflection. The cantilever endpoint does the same for a beam fixed at one end, returning the reaction force and fixing moment, the maximum bending moment and the free-end deflection. The section endpoint gives the cross-section properties that those deflections need: the second moment of area (moment of inertia) and the section modulus for a rectangle, a solid circle or a hollow circular pipe. Every result lists the formula used, so you can show your working. Use consistent units — in SI, load in newtons, distributed load in N/m, lengths in metres, E in pascals and I in m⁴ give moments in N·m and deflections in metres. Everything is computed locally and deterministically, so it is instant and private. Linear-elastic, small-deflection theory — a learning and estimating tool, not a substitute for a qualified structural engineer on a real design. Ideal for engineering and architecture tools, education and physics apps, maker and DIY calculators, and CAD helpers. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is structural beam statics; for bolt and fastener torque use a torque API.

api.oanor.com/beam-api