D1.D.2.3 AASHTO (LRFD) Design Parameters

The following table outlines the parameters that can be used with the AASHTO (LRFD) code along with the default values used if not explicitly specified.

Table 1. AASHTO (LRFD) Design Parameters
Parameter Name	Default Value	Description
BEAM	1.0	Identify where beam checks are performed: 0 = Perform design at ends and those locations specified in the SECTION command. 1 = Perform design at ends and 1/12th section locations along member length.
DMAX	1000	Maximum allowed section depth (in current length units) for a section to be selected with the SELECT command.
DMIN	0	Minimum allowed section depth (in current length units) for a section to be selected with the SELECT command.
DFF	0	Deflection Length/Max allowable local deflection If set to 0, (default) then no deflection check is performed.
DJ1	Start joint of member	Joint No. denoting starting point for calculating Deflection Length.
DJ2	End joint of member	Joint No. denoting ending point for calculating Deflection Length.
GRADE	1	Grade of Steel: 1: Grade 36 2: Grade 50 3 Grade 50W 4: Grade 70W 5: Grade 100/100W Refer to AASHTO LRFD, Table 6.4.1-1
KY	1.0	Effective length factor to calculate slenderness ratio for buckling about local y-axis. Usually this is the minor axis.
KZ	1.0	Effective length factor to calculate slenderness ratio for buckling about local z-axis. Usually this is the major axis.
LY	Member Length	Length to calculate slenderness ratio for buckling about the local Y axis.
LZ	Member Length	Same as above except in local z-axis.
MAIN	0.0	Flag for checking slenderness limit: 0.0 =check for slenderness 1.0 =suppress slenderness check
NSF	1.0	Net Section Factor. Ratio of (Net Area)/(Gross Area)
NSF	1.0	Net section factor for tension members.
TRACK	0	Level of detail in Output File: 0 = Print the design output at the minimum detail level. 1 = Print the design output at the intermediate detail level. 2 = Print the design output at maximum detail level..
UNB	Member Length	Unsupported length of bottom flange. Used for calculating the moment of resistance when the bottom of beam is in compression.
UNT	Member Length	Unsupported length of top flange. Used for calculating the moment of resistance when top of beam is in compression.