Each beam element uses the Euler–Bernoulli stiffness matrix k = EI/L³ multiplied by the standard four-degree beam matrix. The global system solves K u = F. Element end forces produce shear and bending diagrams.
Distributed loads use consistent nodal loading. Point loads use cubic beam shape functions. Support presets restrain vertical displacement and, for fixed supports, rotation.
Flexural screening starts with Mn = Fy × Zx. Factors account for local slenderness, lateral-torsional buckling, openings, corrosion, fire, and selected composite action. Shear screening uses Vn = 0.6 Fy Aw.
Resistance factors depend on LRFD or ASD selection. These equations are intentionally transparent but do not replace every clause, exception, or stability provision of a governing standard.
Deflection comes directly from the finite-element displacement solution using service combinations. The allowable value is the smaller of the selected span ratio and absolute displacement limit.
The first-mode frequency is estimated from beam stiffness and distributed mass. Floor vibration design usually needs effective floor width, damping, activity criteria, acceleration limits, and system interaction.
- Choose the standard, design method, beam configuration, total length, and restraint assumptions.
- Enter dead, live, roof, snow, wind, seismic, equipment, construction, or repeating reactions as separate load rows.
- Select the steel grade and section family. Set depth, width, weight, utilization, cost, and carbon limits.
- Define unbraced length, bearing length, deflection limits, vibration criteria, and any special conditions.
- Calculate and review the governing section, utilization ratios, diagrams, reactions, warnings, and alternatives.
- Replace generic catalog values with verified official properties before issuing a design or purchasing steel.
This application is designed for preliminary sizing, teaching, option comparison, and early project coordination. It cannot establish complete structural adequacy by itself. Real projects require verified loads, diaphragm behavior, load paths, connections, bracing, support stiffness, construction sequence, fire protection, corrosion exposure, fatigue, vibration, robustness, fabrication tolerances, and local regulations.
The generic section catalog is intentionally broad and geometry-based. Its designations are marked DEMO. Do not treat them as certified rolled shapes. Use verified manufacturer or standards-body data for final work. Advanced conditions such as web openings, composite action, fire, and corrosion receive simplified screening factors plus warnings.
Actions and load paths
- Confirm dead loads from slabs, walls, finishes, ceilings, services, equipment, and the final selected beam.
- Confirm live-load values, reductions, pattern loading, concentrated loads, and occupancy changes.
- Review snow drift, rain ponding, wind uplift, seismic actions, accidental actions, and construction loading.
- Trace reactions into columns, walls, foundations, transfer members, diaphragms, and lateral systems.
- Check load eccentricity, torsion, load application above the shear center, and secondary framing reactions.
Strength and stability
- Verify major-axis and minor-axis flexure using the exact section classification and current code equations.
- Verify shear yielding, shear buckling, tension-field action, moment-shear interaction, and panel-zone effects.
- Confirm lateral-torsional buckling length, brace strength, brace stiffness, deck attachment, and construction-stage restraint.
- Check flexural, torsional, and flexural-torsional buckling when axial compression accompanies bending.
- Evaluate local concentrated-force limit states, including web yielding, crippling, sidesway buckling, and compression buckling.
Serviceability
- Separate dead, superimposed dead, live, roof, snow, and construction-stage deflections.
- Check total, incremental, differential, cantilever-tip, cladding, partition, glazing, and drainage criteria.
- Review floor vibration using system mass, effective floor width, damping, walking paths, and sensitive equipment limits.
- Coordinate camber, erection tolerances, slab thickness, ponding, finish elevations, and connection rotation.
Connections and supports
- Design simple shear, moment, seated, end-plate, clip-angle, fin-plate, splice, and base connections as applicable.
- Check bolts, welds, block shear, net-section rupture, bearing, tear-out, prying, slip, and local deformation.
- Verify support bearing length, masonry or concrete bearing, grout, plates, stiffeners, and anchor arrangements.
- Review connection eccentricity, cope geometry, access holes, notches, web openings, and reinforcement plates.
- Confirm continuity plates, doubler plates, panel zones, column flange bending, and column web limit states.
Composite, fire, fatigue, and durability
- For composite beams, verify effective slab width, deck orientation, stud resistance, spacing, placement, and degree of interaction.
- Check unshored construction, wet concrete loading, construction deflection, stud fatigue, and slab reinforcement.
- Establish fire exposure, required resistance period, protection system, section factor, restraint, and elevated-temperature properties.
- Classify fatigue details, determine stress ranges and cycles, and review crane, bridge, machinery, or cyclic service.
- Specify coatings, galvanizing, weathering steel conditions, drainage, corrosion allowance, inspection, and maintenance access.
Documentation and quality control
- Use official section tables and confirm grade availability, rolling tolerances, substitutions, and regional supply.
- Record code editions, national annexes, importance categories, risk categories, load combinations, and assumptions.
- Coordinate member marks, elevations, openings, penetrations, bracing points, connection forces, and erection sequencing.
- Arrange independent checking, calculation review, drawing review, shop drawing review, inspection, and field verification.
| Module | Current behavior | Recommended production extension |
|---|---|---|
| Section database | Large generic geometry catalog with DEMO designations. | Import licensed or official section properties, availability, grades, and manufacturer metadata. |
| Load combinations | Common LRFD, ASD, Eurocode-style, service, and custom JSON combinations. | Add exact jurisdictional combinations, companion factors, directional rules, notional loads, and pattern loading. |
| Beam solver | Two-degree Euler–Bernoulli beam finite elements with consistent nodal loads. | Add shear deformation, springs, releases, variable stiffness, second-order effects, and nonlinear supports. |
| Moving loads | User-entered point positions with a review warning. | Add influence lines, vehicle definitions, lane placement, dynamic allowance, and position envelopes. |
| Flexure | Plastic capacity with transparent local and LTB screening reductions. | Implement every governing-code limit state, Cb procedure, moment gradient, monosymmetry, and inelastic equations. |
| Shear | Web shear yielding screen with opening and durability factors. | Add web slenderness, buckling coefficients, tension-field action, stiffeners, and moment-shear interaction. |
| Concentrated forces | Simplified bearing screen. | Add web local yielding, crippling, sidesway buckling, compression buckling, stiffener, and doubler design. |
| Composite beam | Selectable degree-based stiffness and resistance multiplier. | Add transformed properties, effective width, stud resistance, partial interaction, shored stages, and deck rules. |
| Vibration | Simplified first-mode frequency estimate. | Add walking response, acceleration, damping, modal mass, rhythmic excitation, and sensitive equipment criteria. |
| Fire | Temperature and time screening reduction with protected-steel option. | Add thermal analysis, section factor, protection properties, restraint, combinations, and code fire resistance equations. |
| Fatigue | Review flag and report warning. | Add detail categories, stress ranges, cycle spectra, cumulative damage, and inspection requirements. |
| Reports | Printable HTML, CSV candidate export, and JSON calculation export. | Add signed PDF reports, revision history, calculation references, diagrams, equations, and company branding. |
| Persistence | Browser local storage for reusable inputs. | Add authenticated projects, database revisions, audit trails, permissions, comments, and team collaboration. |
| Interoperability | JSON input structure available through the page. | Add REST endpoints, BIM identifiers, IFC mapping, analysis-model import, and spreadsheet integration. |