Design symbol notation

A calculated result is full of symbols: φMsx, αm, rf. This page is the dictionary the product itself uses - the same table that fills the Notation appendix of the PDF report (turn it on in the Report Designer). If a symbol prints in a calc sheet, it is defined here with the clause it comes from.

The table is scoped to the symbols the engine actually emits, not the whole of each standard's notation, so every row is a claim about what the product prints.

AS 4100:2020 steel member design

AS 4100:2020 (Amdt 1)

Factors and material

Symbol	Meaning	Clause

| `φ` | Capacity factor | Cl 3.4 | | `fy` | Yield stress of the overall section | | | `γ` | Section interaction exponent, 1.4 + N*/φNs | Cl 8.3.4 |

Section properties

Symbol	Meaning	Clause

| `Zex` | Effective section modulus, major axis | Cl 5.2.2 | | `λe` | Element slenderness | Cl 5.2.2 | | `λep` | Element slenderness limit for a compact (plastic) element | Cl 5.2.2 | | `λey` | Element slenderness limit for a non-compact (yield) element | Cl 5.2.2 | | `kf` | Form factor for a compression member | Cl 6.2.2 | | `An` | Net area of the section (gross area less Arf and Arw) | | | `Ae` | Effective area of the section | Cl 6.2.2 | | `Arf` | Area of bolt holes removed from the flanges | | | `Arw` | Area of bolt holes removed from the web | |

Effective lengths

Symbol	Meaning	Clause

| `Le` | Bending effective length, major axis | Cl 5.6.3 | | `Lx` | Compression effective length, major axis | Cl 6.3.2 | | `Ly` | Compression effective length, minor axis | Cl 6.3.2 | | `Lz` | Torsion effective length | | | `kt` | Twist restraint effective length factor | Cl 5.6.3 | | `kl` | Load height effective length factor | Cl 5.6.3 | | `kr` | Lateral rotation effective length factor | Cl 5.6.3 |

Flexure

Symbol	Meaning	Clause

| `φMsx` | Section moment capacity, major axis | Cl 5.2.1 | | `φMsy` | Section moment capacity, minor axis | Cl 5.2.1 | | `φMbx` | Member moment capacity, major axis (lateral-torsional buckling) | Cl 5.6.1 | | `φMf` | Moment capacity of the flange | Cl 5.12.2 | | `αm` | Moment modification factor | Cl 5.6.1.1 | | `αs` | Bending member slenderness reduction factor | Cl 5.6.1.1 |

Compression

Symbol	Meaning	Clause

| `φNs` | Section capacity in compression | Cl 6.2 | | `φNcx` | Member capacity in compression, major axis | Cl 6.3.3 | | `φNcy` | Member capacity in compression, minor axis | Cl 6.3.3 | | `λn` | Modified compression member slenderness | Cl 6.3.3 | | `αc` | Compression member slenderness reduction factor | Cl 6.3.3 | | `αb` | Compression member section constant | Cl 6.3.3 |

Tension

Symbol	Meaning	Clause

| `φNt` | Section capacity in tension | Cl 7.2 | | `Kt` | Correction factor for eccentric effects in a tension member | Cl 7.3 |

Shear

Symbol	Meaning	Clause

| `φVv` | Shear capacity of the web | Cl 5.11 | | `φVvm` | Shear capacity reduced for coincident bending | Cl 5.12.3 |

Design actions

Symbol	Meaning	Clause

| `N*` | Design axial force (compression positive) | | | `M*x` | Design bending moment, major axis | | | `M*y` | Design bending moment, minor axis | | | `Vx*` | Design shear force, major axis | | | `Vy*` | Design shear force, minor axis | |

Combined actions

Symbol	Meaning	Clause

| `φMrx` | Section moment capacity, major axis, reduced for axial force | Cl 8.3.2 | | `φMry` | Section moment capacity, minor axis, reduced for axial force | Cl 8.3.3 | | `φMix` | Member in-plane moment capacity, major axis | Cl 8.4.2.2 | | `φMiy` | Member in-plane moment capacity, minor axis | Cl 8.4.2.2 | | `φMox` | Member out-of-plane moment capacity, major axis | Cl 8.4.4 | | `φMtx` | Lesser of φMrx and φMox | Cl 8.4.5.2 | | `φMcx` | Lesser of φMix and φMox | Cl 8.4.5.1 | | `φMcy` | Lesser of φMiy and the minor-axis out-of-plane capacity | Cl 8.4.5.1 |

Web bearing

Symbol	Meaning	Clause

| `r*` | Design bearing force at a directly supported end | Cl 5.13.2 | | `φRby` | Design bearing yield capacity | Cl 5.13.3 | | `φRbb` | Design bearing buckling capacity | Cl 5.13.4 | | `φRb` | Design bearing capacity, the lesser of φRby and φRbb | Cl 5.13.3 |