TR.23.1 Member Truss Specification
This command may be used to model a specified set of members as TRUSS members.
This specification may be used to specify TRUSS type members in a PLANE, SPACE or FLOOR structure. The TRUSS members are capable of carrying only axial forces. Typically, bracing members in a PLANE or SPACE frame will be of this nature.
General Format
MEMBER TRUSS
member-list (TENSION f1)
Where:
| Parameter | Description |
|---|---|
| TENSION f1 | optional initial tension in the truss member, in current units |
Note: For Nonlinear CABLE ANALYSIS Only: The Tension parameter is ignored except in Nonlinear Cable Analysis. For that analysis type, a truss with pretension is considered to be nonlinear (large displacement). In this analysis type, trusses without preload are assumed to be linear members that carry both tension and compression regardless of this command.
This command is superfluous when a TRUSS type structure has already been specified using the command STAAD TRUSS.
Notes
- The TRUSS member has only one degree of freedom-the axial deformation. Note also that Member Releases are not allowed. Selfweight and transverse loads may induce shear/moment distributions in the member.
- Member loads are lumped at each end, whereas a frame member with moment releases only retains the axial component of the applied member load.