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).
Tip: You may select the tool in the Geometry Tools group on the Utilities ribbon tab in the STAAD.Pro Analytical Modeling workflow for modifying analytical members which are pointing in the wrong direction
- A member in one physical member group can not be part of any other physical member group.
PMEMBER
option can only be used for codes which
explicitly support that command. Refer to the appropriate design code
specification to confirm if that code supports
PMEMBER
design.
Description
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:
DEFINE PMEMBER
Member-list PMEMBER pmember-no
Example
JOINT COORDINATE
1 0 0 0 6 10.0 0 0
MEMBER INCIDENCE
1 1 2 5
DEFINE PMEMBER
1 TO 5 PMEMB 1
To define the member property of a Physical Member, the following command is used:
PMEMBER PROPERTY
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:
PMEMBER CONSTANTS
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.
PMEMBER LOAD
command. Refer to
TR.32.2.1 PMember Load Specification for
details.
Design parameters are available for use with PMEMBERS by using the PMEMB list. The following syntax is used:
parameter value PMEMB pmember-list
Example
RATIO 1.05 PMEMB 1 2
ALL
for a
PMEMB
list, except for
CODE CHECK
or
SELECT
commands.
After the analysis, the Post Analysis results of a PMEMBER can be seen by using the following command:
PRINT PMEMBER FORCE
This command will produce member forces for all the analytical members in the group.