D6.A.5 Design Parameters

The design parameters outlined in the following table may be used to control the design procedure. These parameters communicate design decisions from the engineer to the program, thus allowing the engineer to control the design process to suit an application's specific needs.

The default parameter values have been selected as frequently used numbers for conventional design. Depending on the particular design requirements, some or all of these parameter values may be changed to exactly model the physical structure.

Note: Once a parameter is specified, its value stays at that specified number until it is specified again. This is the way STAAD.Pro works for all codes.

Table 1. French Steel Design Parameters
Parameter Name	Default Value	Description
CODE	FRENCH	Design code to follow. See TR.48.1 Parameter Specifications.
BEAM	0.0	0) design only for end moments and those at locations specified by `SECTION` command. 1) calculate moments at tenth points long the beam, and use maximum Mz for design.
C1	1.0	Parameter used in clause 5.21 in the calculation of M(D), the critical twisting moment and as shown in CM 66 Addendum 80, table 5, usual range from 0.71 to 4.10
C2	1.0	Parameter used in clause 5.21 in the calculation of M(D), the critical twisting moment and as shown in CM 66 Addendum 80, table 5, usual range from 0.0 to 1.56
DMAX	100.0 cm.	Maximum allowable depth (used in member selection).
DMIN	0.0 cm.	Minimum allowable depth (used in member selection).
FYLD	250.0 MPa	Yield strength of steel.
KY	1.0	K value for axial compression buckling about local Y-axis. Usually, this is the minor axis.
KZ	1.0	K value for axial compression buckling about local Z-axis. Usually, this is the major axis.
LY	Member Length	Length to calculate slenderness ratio about Y-axis for axial compression.
LZ	Member Length	Length to calculate slenderness ratio about Z-axis for axial compression.
NSF	1.0	Net section factor for tension members.
RATIO	1.0	Permissible ratio of actual load effect and design strength.
SAME	0.0	Controls the sections to try during a SELECT process. 0) Try every section of the same type as original (see note a below) 1) Try only those sections with a similar name as original, e.g., if the original is an HEA 100, then only HEA sections will be selected, even if there are HEM’s in the same table.
TRACK	0.0	Level of detail in output: 0) Suppress printing of all design strengths. 1) Print all design strengths
UNF	1.0	Unsupported length provided as a fraction of actual member length used for lateral-torsional buckling calculation. Note: If both `UNF` and `UNL` parameters are specified, the effective length used is `UNF`×`UNL`.
UNL	Member Length	Unsupported length for calculating allowable bending stress. Used for the lateral-torsional buckling calculation. Value should be in the current units of length.

For angles, if the original section is an equal angle, then the selected section will be an equal angle and vice versa for unequal angles.