The design of a member for seismic actions is divided into four design checks and four design constraints. The four design checks consider the axial force limits of clause 12.8.3.1 and the user can choose to check the member for the General Axial Limit (clause 12.8.3.1(a)), Axial Compression Limit for both major and minor axes (clause 12.8.3.1(b)) and the Axial Force Limit (clause 12.8.3.1(c)). The Axial Force Limit is applied using N*_g=N*.

The four design constraints check the member for the Beam, Material and Section Geometry requirements of clauses 12.4.1, 12.5.1 and 12.7.2.1. The user can select which of these constraints are to be applied to the design of a member via the Seismic dialog.

When checking or designing members using NZS3404 it is necessary to specify the category of a member. The category of a member is specified by choosing the appropriate category from the list provided in the Seismic Dialog. The default category for all members is category 4.

To set the seismic design properties of a member

Ø  Select the required members in the Frame window

Ø  Choose Seismic… from the Design menu

Ø  Choose the member category from popup menu

Ø  Select each of the design constraints to be tested

Ø  Identify if the member is part of the seismic resisting system.

Ø  Click OK