D12.B.3 Design Parameters

Design parameters communicate specific design decisions to the program. They are set to default values to begin with and may be altered to suite the particular structure.

Table 1. Design Parameters for NORSOK N-004 design code
Parameter Name	Default Value	Description
CODE	none	Must be specified as `NORSOK`. Note: Do not use the shortened NOR, as this initiates an NS3472 design.
BEAM	0	Beam segment locations for design: 0) design only for end moments and those at locations specified by `SECTION` command. 1) Perform design for moments at twelfth points along the beam.
CMY	0.85	Reduction factor C_m corresponding to the Y axis.
CMZ	0.85	Reduction factor C_m corresponding to the Z axis.
DFF	None (Mandatory for deflection check)	"Deflection length"/maximum allowable local deflection.
DJ1	Start Joint of member	Joint No. denoting start point for calculation of deflection length
DJ2	End Joint of member	Joint No. denoting end point for calculation of deflection length
DMAX	100.0 [cm]	Maximum allowable depth of steel section.
DMIN	0.0 [cm]	Minimum allowable depth of steel section.
FYLD	235 [MPa]	Yield strength of steel, f_y (St37) Note: Note, if the `SGR` value is specified, then the associated value of f_y for that steel grade will be used for a member in lieu of the `FYLD` value.
FU	420 [MPa]	Ultimate Tensile Strength of Steel
HYD	0.0	The Y-coordinate, current units, of the maximum water level with respect to the origin. Note: If `SET Z UP` command has been specified, then yi will be the Z co-ordinate of the max water level. For `HYD` > 0, the value of max. hydrostatic pressure calculated is reported for each member in a `TRACK 2.0` output.
KY	1.0	Effective length factor, k, in local Y-axis, usually minor axis.
KZ	1.0	Effective length factor, k, in local Z-axis, usually major axis.
LSR		Length of Tubular between Stiffening Rings. This value is required to calculate Design Hoop Stress due to Hydrostatic Pressure to check Hoop Buckling as per clause 6.3.6.1.
LX		Effective length for lateral torsional buckling.
LY	Member Length	Length in local Y axis for slenderness value KL/r
LZ	Member Length	Length in local Z axis for slenderness value KL/r
MAIN	0	Option to design for slenderness. 0) Check for slenderness 1) Do not check for slenderness Any value greater than 1.0 is used as the limit for slenderness in compression.
PSD	0.0	Water pressure at each section in absence of `HYD`.
RATIO	1.0	Permissible ratio of the actual to allowable stresses.
SGR	0	Steel Grade per EC3 (EN 1993-1-1:2005): 0) S 235 grade steel 1) S 275 grade steel 2) S 355 grade steel 3) S 420 grade steel 4) S 460 grade steel
TMAIN	180.0	Slenderness limit in tension. Slenderness limit is checked based the `MAIN` parameter.
TRACK	0	Output detail: 0) Only a summary of the design checks performed is printed. 1) Print basic member design output only. 2) All the details of the member checks and the various clause checks performed are printed. 3) Prints detailed member check and joint check results. 4) Print detailed joint design output.

Notes

C1 and C2 Parameters

The default values of these coefficients are taken from Table 6-4 of N-004 and depend on the joint and load type:

Table 2. Default values for `C1` and `C2` parameters
Joint Type	`C1`	`C2`
T or Y joints under brace axial load	25	11
X joints under brace axial load	20	22
K joints under balanced axial load	20	22
All joints under brace moment loading	25	30

Note: These values can be changed by setting the K, X, and Y values in the external geometry file.

Example

Note: This is a partial example containing only the information pertaining to the NORSOK N-004 steel design code; used at the end of the input file.

* Check tubular members according NORSOK N-004
CODE NORSOK
HYD 3.0 MEMB 1 TO 3
PSD 10 MEMB 7 10
SGR 2 MEMB 1 TO 3 7 10
TRACK 2 MEMB 1 TO 3 7 10
CHECK CODE MEMB 1 TO 3 7 10