Structural · Engineer advanced

Preliminary steel beam sizing

Iterate the local ISMB catalog against declared gravity loads, elastic bending, simplified shear, and service deflection. This is an engineering pre-check—not a construction design or approval.

Preliminary sizing only. Confirm the complete load path, Nepal code edition, section properties, lateral restraint, connection design, seismic role, and construction conditions with a qualified structural engineer.

Clear span (m)Use the measured support-to-support span. Final design span depends on the structural model.Support conditionDead load, excluding beam (kN/m)Live load (kN/m)Select or verify this from NBC 103 for the actual occupancy and tributary width.NBC 103 occupancy presetPreset values are a screening aid; verify current NBC 103 and actual use.Tributary width (m)Used only when an NBC 103 occupancy preset is selected.Wind line load (kN/m, optional)Enter the project design line load from NBC 104; no national default is assumed.Calculate wind line load from NBC 104 screening inputsWind zoneWind tributary width (m)Wind terrain/height factorWind probability factorWind topography factorWind pressure coefficientSnow line load (kN/m, optional)Enter the project design snow line load from NBC 106.Calculate snow line load from site snow inputGround snow load (kN/m²)Snow tributary width (m)Snow shape coefficientSnow exposure coefficientSnow thermal coefficientSeismic line load (kN/m, optional)Enter the engineer-derived seismic effect; this screen does not calculate base shear.Combination envelopePoint load (kN, optional)Point-load position (0–1)Axial compression (kN, optional)Explicit torsion (kN·m, optional)Load eccentricity (m, optional)Measured from the shear centre; flange load paths need engineer confirmation.Deflection limit (L/x)Steel gradeDesign methodStructural roleCompression-flange unbraced length (m)Lateral restraintBearing length (mm)Web stiffenersConnection shear capacity (kN, optional)Support bearing capacity (kN, optional)

Code references carried by this result: NBC 103 occupancy loads, NBC 104 wind, NBC 105:2025 seismic design, NBC 106 snow, and NBC 111 steel. Load values and final combinations remain engineer-entered.

Preliminary section check

ISMB 225

Simply supported · 6 m · ISMB catalog

M max37.38 kN·m

V max24.92 kN

Deflection20.4 mm

Allowed24.0 mm

Self-weight0.31 kN/m

Iterations6

Reaction24.92 kN

Classplastic

Governing strength: 1.0D+1.0L

Governing service: 1.0D+1.0L

Torsion: 0.00 kN·m · Axial: 0.0 kN

Checks

Elastic bending demandGoverning 1.0D+1.0L: M demand / preliminary working-stress capacity = 74%.

Shear demandGoverning 1.0D+1.0L: V demand / simplified web-area capacity = 6%.

Service deflectionGoverning 1.0D+1.0L: calculated deflection is 20.4 mm against 24.0 mm allowed.

Lateral-torsional bucklingPreliminary elastic LTB screen: 74% utilization at Lb = 6.00 m; engineer must verify restraint, moment gradient, and code curve.

Local plate slenderness / section classISMB 225 is preliminarily plastic; flange/web ratios use an IS 800-style epsilon screen and require catalog/source verification.

Web bearing and cripplingSimplified web bearing utilization 19%; web slenderness utilization 15% using 100 mm bearing length. Stiffener condition: unknown.

Axial plus bending interactionPreliminary interaction = 74% including 0.0 kN axial compression and torsion.

Torsion / eccentric loadNo explicit eccentricity or torsional moment supplied.

ConnectionsConnection capacity is not supplied; bolts/welds, block shear, prying, and detailing remain open.

Support bearingSupport bearing capacity is not supplied; verify seat length, bearing material, and local web stiffening.

Nepal seismic detailingGravity-only role selected; confirm the member is not part of the lateral-force-resisting system.

Preliminary sizing only. This result is not a structural approval, permit submission, construction drawing, or safety certificate.

Closed-form single-span beam response used for the selected support condition.

Live load is engineer-entered as a line load; confirm occupancy and tributary width against NBC 103.

Load envelope uses service-level combinations. NBC 103/104/105/106 values remain engineer-entered and project-specific.

Nepal provenance: NBC 103/104/105/106/111 references must be confirmed against the project and current code edition. Formula version steel-beam-preliminary-2026-09-v1.

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