• This tool is intended to design member segments, i.e. portions of a member between points of full, partial or lateral restraint. Flexure and compression design lengths can be specified by the user.

• Members are designed about their principal axes for bending moment checks / compression buckling checks, and geometric axis for shear force checks. User loading inputs will be converted between geometric and principal axes (based on the angle of rotation to principal axes) as required for capacity checks.
• Selecting a Custom section assumes that the section is fabricated out of structural steel plate complying with AS/NZS 3678. These plates are assumed to be heavily welded (HW) for slenderness checks.
• Shear and flexural loading is assumed to be applied through the shear centre of the section. Any torsional effects due to eccentric loading are not considered.
• Axial loading is assumed to be applied concentrically to the section. Any additional bending effects due to eccentric loading are not considered.
• This tool does not carry out serviceability or deflection checks. All checks are for ultimate limit state only.
• Section yield strength is taken as the lesser of flange and web yield stress, unless noted otherwise.
• This calculator only supports unequal angles with a longer vertical leg.

Sections are classified for major and minor principal axis bending according to NZS 3404 Clause 5.2.2. The governing element within a section is used to assign its overall classification.

This tool carries out a comprehensive set of section and member capacity checks in accordance with NZS 3404, including:

• Moment Capacity: Section moment capacity is calculated using NZS 3404 Clause 5.2.1 for the principal Z and Y axis in both directions of bending. To determine the major axis member bending moment capacity (Mb.z), it first needs to be determined if the member satisfies conditions for Full Lateral Restraint in accordance with Clause 5.3.2. If a member achieves Full Lateral Restraint, its member bending moment capacity (Mb.z) is equal to the section moment capacity.
• Shear Capacity: Shear capacity is always checked about a sections geometric axes (Vertical Y and Horizontal Z). Loads will be converted into geometric axes direction where required. Note, NZS 3404 provides minimal guidance on the design of open sections in minor axis (Z-direction) shear. The calculations adopted by this module are based on available research and engineering logic. Care should be taken when designing sections subject to high minor axis shear loading.
• Compression Capacity: All compression capacity calculations assume that the member is loaded concentrically.
• Torsion Capacity: Torsion capacity calculations checks are not carried out by this calculator.

SkyCiv Quick Design now supports a range of structural engineering tools for New Zealand Standards. This includes:

• Steel Design for Members, Bolts and Weld Connections
• Cold Formed Steel Member Design
• Aluminum Member Design
• Concrete Column Design
• Reinforcement Lap Length

You can find all our New Zealand Quick Design tools in the SkyCiv Quick Design Library

SkyCiv offers a wide range of Cloud Structural Analysis and Engineering Design Software, including:

• SkyCiv Quick Design
• AS/NZS 1664 Aluminium Design
• AS/NZS 4600 Purlin Design
• AS 3600 Concrete Shear Wall Design
• AS 2870 Residential Slab on Grade Design
• AS/NZS 1576 Scaffolding Design
• AS 4055 Wind Load Calculator
• AS 4100 Bolt Group Calculator
• AS 4600 Cold-Formed Steel Design Calculator

As a constantly evolving tech company, we're committed to innovating and challenging existing workflows to save engineers time in their work processes and designs.