Anatomy of a Calculation

Every connection calculator in the Hub uses the same layout. Learn it once and every other calculator reads the same way. The 49 minute webinar walk-through covers the same ground in depth, with live examples.

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Key Properties

The top section. Member sizes, material grades, orientation and the connection configuration. This section is gating. Changing a member size or the connection type can add, remove or reword the inputs below it, so work top to bottom rather than jumping around. Where a calculator supports several configurations (for example conventional versus extended plate, or beam on one side versus two sides), that toggle sits here. Typical inputs:

• Beam and column or girder HSS sections, and grade (commonly ASTM A500 Grade C or A1085)
• Design method, ASD or LRFD
• Connection type and plate configuration
• Member orientation, rotatable in top and side views to match field conditions

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Plate, weld and bolt inputs

Geometry for the connecting elements.

• Plate thickness, width, length and setback
• Fillet weld size
• Bolt size, grade, thread condition (included or excluded from the shear plane), and whether the joint is slip-critical with its faying surface class
• Vertical and horizontal bolt spacing, and edge distances

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Applied Loads

Add or remove load cases and edit magnitudes. Dead, live, snow, wind and seismic are supported. You generally have two entry modes:

• Individual load inputs. Enter unfactored loads by type and let the sheet generate and sweep the ASCE 7 load combinations. The governing combination is reported per limit state.
• Pre-factored loads. Enter demands you have already factored. Faster when your analysis model already produces factored envelopes.

Seismic capacity design is the exception. Where a calculator runs AISC 341-22 checks, it requires individual load inputs so the overstrength combination is applied explicitly, and factored entry is disabled while seismic is active.

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Summary

The live diagram plus the headline result. The diagram redraws from your geometry, including cope dimensions, plate positions, bolt patterns and member rotation. Treat it as your first check: if it does not look like the connection you are detailing, an input is wrong. Below it, utilisation is reported as a colour-coded percentage per group, for example:

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Expandable calculations

Every limit state expands to show the full working: the equation as written in the code, the substituted values, the result, and the clause reference. This is what makes the output reviewable rather than a black box, and it is what your checker will read.

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Limits of applicability

Most HSS connection provisions only apply within geometric and material bounds, for example the chord slenderness and width ratio limits in AISC 360-22 Table K2.1A and the equivalents in AISC Design Guide 24. Where a calculator gates on those limits, it says so and suppresses the downstream limit states rather than reporting a result you cannot rely on. An unsupported configuration produces an explicit message, not a silent pass.

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Related

• Getting started
• Exporting reports and details