D9.C.7Design Parameters
Parameter Name | Default Value | Description |
---|---|---|
CODE | - |
Must be specified as
Design code to follow. See TR.48.1 Parameter Specifications. |
BEAM | 1.0 |
Locations of design:
|
CAN | 0 |
Specifies the method used for deflection checks
|
CB | 0 |
C value from the AIJ code. Refer to D9.C.5 Member Capacities Bending Stress for how C is calculated and applied. Use 0.0 to direct the program to calculated Cb. Any other value be used in lieu of the program calculated value. |
DFF | None(Mandatory for deflection check) |
Deflection Length/ Maximum allowable local deflection |
DJ1 | Start Joint of member | Joint No. denoting starting point
for calculation of
Deflection Length(See note b) |
DJ2 | End Joint of member | Joint No. denoting end point for
calculation of
Deflection Length(See note b) |
DMAX | 100 cm | Maximum allowable depth for member. |
DMIN | 0.0 cm | Minimum allowable depth for member. |
KY | 1.0 | K value in local y-axis. Usually, this is the minor axis. |
KZ | 1.0 | K value in local z-axis. Usually, this is the major axis. |
LY | Member Length | Length in local y-axis to calculate slenderness ratio. |
LZ | Member Length | Same as above except in z-axis |
FYLD | 235 MPa | Yield strength of steel in megapascal.
The material strength value is first
take from the |
MAIN | 200 | Allowable
Slenderness Limit for Compression Member
Any value greater than 1 = Allowable KL/r in compression (up to 250) |
MBG | 0 | Specifies how to calculate the
section modulus about the Z-Z axis for H-shape, I-shape, and channel sections
when performing major axis bending checks:
|
MISES | 1 |
Von Mises check options:
For more details, refer to D9.C.10 Von Mises Stresses Check. |
NSF | 1.0 | Net section factor for tension members. |
RATIO | 1.0 | Permissible ratio of the actual to allowable stresses. |
SLF | 1 | Slender section design option:
|
TMAIN | 400 |
Allowable Slenderness Limit for Tension Member
Any value greater than 1 = Allowable KL/r in tension. |
TRACK | 0.0 |
Level of output detail:
|
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. |
YNG | 0 |
Method for evaluating Young's modulus, E, for equation 5.8:
|
D9.C.7.1Notes
-
When performing the deflection check, you can choose between two methods. The first method, defined by a value 0 for the
CAN
parameter, is based on the local displacement. Refer to TR.44 Printing Section Displacements for Members for details on local displacement..If the
CAN
parameter is set to 1, the check will be based on cantilever style deflection. Let (DX1, DY1,DZ1) represent the nodal displacements (in global axes) at the node defined byDJ1
(or in the absence ofDJ1
, the start node of the member). Similarly, (DX2, DY2, DZ2) represent the deflection values atDJ2
or the end node of the member.Compute Delta =
Compute Length = distance between
DJ1
andDJ2
or, between start node and end node, as the case may be.Then, if
CAN
is specified a value 1, dff = L/DeltaRatio due to deflection =
DFF
/dff -
If
CAN
= 0, theDeflection Length
is defined as the length that is used for calculation of local deflections within a member. It may be noted that for most cases theDeflection Length
will be equal to the length of the member. However, in some situations, theDeflection Length
may be different. A straight line joiningDJ1
andDJ2
is used as the reference line from which local deflections are measured.For example, refer to the figure below where a beam has been modeled using four joints and three members. TheDeflection Length
for all three members will be equal to the total length of the beam in this case. The parametersDJ1
andDJ2
should be used to model this situation. Thus, for all three members here,DJ1
should be 1 andDJ2
should be 4. D = Maximum local deflection for members 1, 2, and 3.PARAMETERS DFF 300. ALL DJ1 1 ALL DJ2 4 ALL
- If DJ1 and DJ2 are not used,
Deflection Length
will default to the member length and local deflections will be measured from original member line. - The above parameters may be used in conjunction with other available parameters for steel design.