AD.2007-07.2.5 Norsok N-004

The design of tubular steel (European round pipe sections) members per NORSOK N-004 Rev 2, October 2004 has been included in STAAD.Pro. The program will perform the member design for ultimate limit states (and optional deflection checks for serviceability). The tubular joints can also be automatically generated and checked per the code.

The NORSOK code has been added to the steel design code list available in STAAD.Pro. Selecting this code allows you to assign parameters, including defining the water level above the origin (for calculating hydrostatic pressure) or the

Note: N-004 refers to the superseded version of Eurocode 3 (DD ENV 1993-1-1) in several places. In such cases, the corresponding clause from the latest version of EC-3 (EN 1993-1-1:2005) has been used in the STAAD.Pro implementation.

To perform a member design per the NORSOK N-004 code

Create a model with steel tubular members.

CAUTION: The Norsok code only supports pipe sections. Errors will be presented in sections other than pipe members are used.
Select NORSOK for the Current Code on the Design | Steel page.
Click the Define Parameters button.

The Design Parameters dialog opens.
Specify parameters as required.

Note: The height of water level above the origin is specified using the HYD parameter. Alternatively, the PSD parameter may be used to define the water pressure.
Close the Design Parameters dialog.
Assign the torsion-related parameters to members as needed, just as you would any other design parameter.

To perform a joint check per the NORSOK N-004 code

Add the CHECK JOINT command to a new PARAMETER manually in the STAAD.Pro input file using the Editor.
Perform an preliminary design by selecting Analyze > Run Analysis….

The program creates an external text file titled filename_JOINTS.NGo which contains the automatically generated chord and brace definitions associated with the nodes included in the CHECK JOINT command. All joints are classified as Y by default.
Open the text file using a text editor program (i.e., Notepad or STAAD Editor).
Manually edit the joint classifications as needed.
(Optional) Edit the Brace and Chord definitions as needed.

Note: The Brace and Chord members at each joint are assumed based on the relative cross section dimensions. Lengths of Chord and Brace members are taken as the analytical beam member length.
Save the text file and the re-analyze the structure

Methodology

Refer to D12.B. Norwegian Codes - Steel Design per NORSOK N-004 for a detailed description of the methodology used in STAAD.Pro for performing steel tube member design per NORSOK N-004.