D8.A.4 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.
Parameter Name | Default Value | Description |
---|---|---|
CODE | - | Must be specified as
IS800 LSD
Design code to follow. See TR.48.1 Parameter Specifications. |
ALPHA | 0.8 | A factor, based on the end-connection type, controlling the
Rupture Strength of the Net Section, as per Section 6.3.3:
|
ANG | 0 |
The location of the angle section through which the axial load passes by. It will only work if the section is single angle. The options are:
If the value is zero, it means the member is loaded through centroid. In that case Flexural-torsional buckling will not be checked. |
ATG | None (Mandatory for Block Shear check) |
Minimum Gross Area in Tension from the bolt hole to the toe of the angle, end bolt line, perpendicular to the line of the force. |
ATN | None (Mandatory for Block Shear check) |
Minimum Net Area in Tension from the bolt hole to the toe of the angle, end bolt line, perpendicular to the line of the force. |
AVG | None (Mandatory for Block Shear check) |
Minimum Gross Area in shear along bolt line parallel to external force. |
AVN | None (Mandatory for Block Shear check) |
Minimum Net Area in shear along bolt line parallel to external force. |
BEAM | 1 |
0) design at ends and those locations specified by the SECTION command. 1) design at ends and at every 1/12th point along member length (default). |
CAN | 0.0 | Beam Type, used for both
deflection checks and the limit of bending strength in clause 8.2.1.2:
|
CMX | 0.9 | Equivalent uniform moment factor for Lateral Torsional Buckling(as per Table 18, section 9.3.2.2) |
CMY CMZ |
0.9 | Cm value in local Y & Z axes, as per Section 9.3.2.2. |
DFF | None(Mandatory for deflection check) |
"Deflection Length" / Maximum allowable local deflection. See TR.40 Load Envelope for deflection checks using serviceability load envelopes. |
DJ1 | Start Joint of 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 | 1000 in. | Maximum allowable depth. |
DMIN | 0.0 in. | Minimum allowable depth. |
FU | 420 MPA | Ultimate Tensile Strength of Steel in current units. |
FXTY | 0 |
The fixity of the connection between gusset plate and each end of member. Any value between 0 and 1 is allowed where 1 = Fixed and 0 = Hinged. Default is hinged. A value between 0 and 1 means the level of fixity that is between hinged and fixed. This value will be used to calculate the coefficients k1, k2 and k3 of table 12 by linear interpolation between their specified values for the two extreme (hinged and fixed) conditions. |
FYLD | 250 MPA | Yield Strength of Steel in current units. |
IMM | 0 |
(LSD method only) Member classification for seismic detailing per Section 12 provisions:
See note b below. |
KX | 1.0 | Effective Length Factor for Lateral Torsional Buckling (as per Table-15, Section 8.3.1) |
KY | 1.0 | K value in local Y-axis. Usually, the Minor Axis. |
KZ | 1.0 | K value in local Z-axis. Usually, the Major Axis. |
LAT | 0 | Specifies lateral support of beam,
as per Section 8.2.1 and 8.2.2, respectively:
|
LST | 0 | Defines the number of
longitudinal stiffeners used:
|
LX | Member Length | Effective Length for Lateral Torsional Buckling (as per Table-15, Section 8.3.1) |
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 | 180 | Allowable Slenderness Limit for
Compression Member (as per Section 3.8)
|
NBL | 1 | The number of bolts connecting
each end of member with the gusset plate. The options are :
|
NSF | 1.0 | Net Section Factor for Tension Member. |
PROFILE | None |
Used to search for the lightest section for the profile(s) specified for member selection. See TR.48.1 Parameter Specifications for details. |
PSI | 1.0 | Ratio of the Moments at the ends
of the laterally unsupported length of the beam, as per Section 9.3.2.1:
|
RATIO | 1.0 | Permissible ratio of the actual to allowable stresses. |
SEISMIC | 0 |
(LSD method only) Specifies if the detailing per Section 12 provisions is performed:
See Note a below. |
STP | 1 | Specifies the section type per Table
2 and Table 10:
|
SSY | 0 |
(LSD method only) Seismic bracing condition along the local Y axis (see note c below):
|
SSZ | 0 |
(LSD method only) Seismic bracing condition along the local Z axis (see note c below):
|
TMAIN | 400 | Allowable Slenderness Limit for Tension Member
(as per Section 3.8)
|
TRACK | 0 | Controls the levels of detail to
which results are reported.
|
TSP | 0 | Spacing of transverse stiffeners. |
TST | 0 | Used to control transverse
stiffeners in design:
|
Notes
- The program will detail members as per the Section 12 provisions if the design parameter SEISMIC is set to 1. It is also recommended that a seismic load using an IS 1893 load definition is in the model. Seismic definitions using other seismic codes are not supported.
- By default, all the members are considered as main members (i.e.,
IMM = 0). The scope for the seismic detailing depends upon the
framing type. The program cannot determine the member or bracing type.
For example, the detailing guidelines for OCBF framing are applicable for X type of bracing only. Therefore, you must assign the appropriate member type (IMM = 2) for the bracing members.
- The response reduction factor, R, will be determined from the parameters SSY and SSZ. If this R differs from the that defined in the seismic load list, the program issues a warning.
- The material strength values are first take from the FYLD and FU parameters if specified. If no design parameters have been specified for material strengths, then the values in the material definition are used. If no material definition has been assigned, then the default parameter values of Fy = 250 MPa and Fu = 420 MPa are assumed.