D1.L.2.3 Design Parameters

The program contains a large number of parameter names which are required to perform design and code checks. These parameter names, with their default values, are listed in the following table.

The default parameter values have been selected such that they are frequently used numbers for conventional design. Depending on the particular design requirements for an analysis, some or all of these parameter values may have to be changed to exactly model the physical structure. For example, by default the KZ value (k value in local z-axis) of a member is set to 1.0, while in the real structure it may be 1.5. In that case, the KZ value in the program can be changed to 1.5, as shown in the input instruction (Section 5). Similarly, the TRACK value of a member is set to 0.0, which means no allowable stresses of the member will be printed. If the allowable stresses are to be printed, the TRACK value must be set to 1.0.

Note: Unlike many other design codes available in STAAD.Pro (which use the BEAM parameter), design per ASME NF 3000 codes in STAAD.Pro is always performed based on forces calculated at 13 sections, including ends.

Table 1. ASME NF 3000 Design Parameters
Parameter Name	Default Value	Description
CODE	-	Must be specified as `NF3000 1989`. Design code to follow. See TR.48.1 Parameter Specifications.
CAN	0	Used for Deflection Check only. 0 = Deflection check based on the principle that maximum deflection occurs within the span between DJ1 and DJ2. 1 = Deflection check based on the principle that maximum deflection is of the cantilever type
CB	1.0	Bending coefficient dependent upon moment gradient 0.0 = CB is calculated itself Any other user-defined value is accepted.
CT	0.75	Reduction Coefficient in computing effective net area of an axially loaded tension member. [Refer NF-3322.8(c)(1)(d)]
CMY CMZ	0.85 for sidesway and calculated for no sidesway	Cm value in local y & z axes
DFF	None(Mandatory for deflection check)	"Deflection Length" / Maximum allowable local deflection
DJ1	Start Jointof member	Joint No. denoting starting point for calculation of "Deflection Length"
DJ2	End Joint of member	Joint No. denoting end point for calculation of "Deflection Length"
DMAX	45 inch	Maximum allowable depth, in current units. Used only with the MEMBER SELECTION command.
DMIN	0.0 inch	Minimum allowable depth, in current units. Used only with the MEMBER SELECTION command.
FYLD	36 KSI	Yield strength of steel at temperature in current units.
FU	60 KSI	Ultimate tensile strength of steel in current units.
KBK	1.0	Stress Limit Factor applicable to the Design Allowable Compressive Axial and Bending stresses to determine the Buckling Limit. Note: Ignored unless `SRL` is set to D.
KS	1.0	Stress Limit Factor applicable to the Design Allowable Tensile and Bending Stresses. Note: Ignored unless `SRL` is set to D.
KV	1.0	Stress Limit Factor applicable to the Design Allowable Shear Stresses. Note: Ignored unless `SRL` is set to D.
KY	1.0	K value in local y-axis. Usually, this is minor axis.
KZ	1.0	K value in local z-axis. Usually, this is major axis.
LY	Member Length	Length to calculate slenderness ratio for buckling about local Y axis.
LZ	Member Length	Same as above except in z-axis (major).
MAIN	0.0	0.0 = check for slenderness 1.0 = suppress slenderness check
NSF	1.0	Net Section Factor for tension member.
PROFILE	None	Used in member selection. See TR.48.1 Parameter Specifications for details.
RATIO	1.0	Permissible ratio of the actual to allowable stresses.
SRL	A	Service level, which defines the service level factors to use for modifying stress values for the service level conditions. Normal Conditions Upset Emergency Faulted - If any of `KS`, `KV`, or `KBK` parameters are not set, a warning is issued that these must be user-defined. Refer to D1.L.5. ASME NF 3000 Service Level Conditions for additional information.
STIFF	Member length or depth whichever is greater	Spacing of stiffeners for plate girder design
STYPE	0.0	0.0 = Normal Steel 1.0 = Austenitic Stainless Steel
TMAIN	240 for main member 300 for "Truss" member	Slenderness limit under tension
TRACK	0.0	Controls the levels of detail to which results are reported. 0 = Minimum detail 1 = Intermediate detail level 2 = Maximum detail
UNB	Member Length	Unsupported length of the bottom* flange for calculating allowable bending compressive stress. Will be used only if flexural compression on the bottom flange.
UNT	Member Length	Unsupported length of the top* flange for calculating allowable bending compressive stress. Will be used only if flexural compression on the top flange.