TR.32.9.1 Selfweight Loads
Used to calculate and apply the self weight of members, plates, and solids in the structure for analysis.
General Format
SELFWEIGHT ( { X | Y | Z } f1) ( LIST member-list | ALL )
Where:
| Parameter | Description |
|---|---|
| X, Y, & Z | represent the global direction in which the selfweight acts. The default direction is along the Y axis. |
| f1 | The factor to be used to multiply the selfweight. The default value is -1.0. |
| member-list | member, plate and/or solid list or group. All list specifications such as explicit list including TO and BY, range (XR, YR, ZR), parallel to (X, Y, Z) and groups are supported. If a group is used, the selfweight command must be repeated for each group. If list is not provided, all structural components are used for body weight calculation unless those are inactive either by INACTIVE command specification or internally set due to TENSION/COMPRESSION ONLY specification. |
Description
This command is used if the self-weight of the members, plates, and solids within the structure is to be considered. The self-weight of every active element is calculated and applied as a uniformly distributed member load.
Note: Surfaces are not included in the selfweight command. The SSELFWT must be used to include the selfweight for surface elements. See TR.32.9.2 Surface Selfweight Load
This command may also be used without any direction and factor specification. Thus, if specified as SELFWEIGHT, loads will be applied in the negative global Y direction with a factor of unity.
Notes
- Density must be provided for calculation of the self weight.
- The selfweight of finite elements is converted to joint loads at the connected nodes and is not used as an element pressure load.
- The selfweight of a plate is placed at the joints, regardless of plate releases.
- The SELFWEIGHT specification for definition of static method of seismic load generator also is capable of accepting a list. Only there is no direction specification for this command.
- Similarly, the SELFWEIGHT specification when used in a Reference Load is also capable of handling a list.
Example
LOAD 1 DEAD AND LIVE LOAD * includes the selfweight of all members, plates, and solids. The following two commands are functionally identical SELF SELFWEIGHT y -1.0 all * * Factored weight for members, plates, and solids 4 through 10 along global x direction SELFWEIGHT X 1.4 LIST 4 TO 10 * Includes weight of al members, plates, and solids associated with the group _PLATEGRP1 SELF X 1.0 _PLATEGRP1