TR.16.2 Physical Members
STAAD.Pro allows grouping analytical predefined members into physical members using a special member group PMEMBER. This command defines a group of analytical, collinear members with same cross section and material property.
To model using PMEMBER, you need to model regular analytical members and then, group those together.
While creating a PMEMBER, the following pre-requisites apply:
- Existence of the analytical members in the member-list.
- Selected members should be interconnected.
- The selected individual members must be collinear (adjacent analytical members must lie within 5°).
- Local axis of the individual members comprising the physical member should be identical (i.e., x, y and z are respectively parallel and in same sense).
- A member in one physical member group can not be part of any other physical member group.
A PMEMBER can be created either in the Analytical Modeling workflow or in the Steel Designer workflow. Analytical Modeling workflow and Steel Designer workflow PMEMBERs will be labeled as M and D, respectively. Modeling workflow PMEMBERs allow variable cross-sections. Steel Designer workflow allows importing of PMEMBERs created in the modeling mode.
To define a Physical Member, the following command is used after the MEMBER INCIDENCE command:
Member-list PMEMBER pmember-no
To define the member property of a Physical Member, the following command is used:
pmember-list PRIS …
The physical member supports all types of member properties available in STAAD.Pro.
If multiple definitions of member properties for a particular analytical member is encountered (e.g., analytical member properties is defined twice, once via PMEMBER PROP command and again via the MEMBER PROP command, then the MEMBER PROP command will override the PMEMBER PROP definition.
To define the material constants of a physical member, the following command is used:
E CONCRETE pmember-list
DEN CONCRETE pmember-list
Any member, which is a part of any PMEMBER is not allowed to be assigned constants explicitly.
Design parameters are available for use with PMEMBERS by using the PMEMB list. The following syntax is used:
parameter value PMEMB pmember-list
RATIO 1.05 PMEMB 1 2