How to set Pin springs in 3D frame analysis

Forum for OpenSees users to post questions, comments, etc. on the use of the OpenSees interpreter, OpenSees.exe

Moderators: silvia, selimgunay, Moderators

Post Reply
shiro
Posts: 59
Joined: Tue May 26, 2020 1:19 am

How to set Pin springs in 3D frame analysis

Post by shiro » Fri Aug 13, 2021 1:02 pm

I posted a question about how to set Pin springs in 3D frame analysis.

As shown below, the X direction is the beams, the Z direction is the girders, and the height is the Y direction.

When I set the section Aggregator as follows, the linear analysis will reflect the bending stress results of the pins in the X direction.
However, when the force is applied in the Z direction by linear analysis, the bending stress result of the pin is not reflected and the result is rigid.

section Aggregator $SecTag1 $MatTagUbig P $MatTagUbig Vy $matID Mz;

In this case, if the following settings are made, the bending stress results of the pins are reflected in the Z direction for both columns and beams by linear analysis.
Is this setting method correct?

section Aggregator $SecTag1 $MatTagUbig P $MatTagUbig Vy $MatTagUbig Vz $matID Mz $matID My;

The matID is a Pinching 4 model with a bending spring as a pin.

I would appreciate it if you could give me some advice and reference materials.



# define section tags:
set ColSecTag 1
set BeamSecTag 2
set GirdSecTag 3


set IDColTransf 1;
set IDBeamTransf 2;
set IDGirdTransf 3;
set ColTransfType Linear ;


geomTransf PDelta $IDColTransf 0 0 1;
geomTransf PDelta $IDBeamTransf 0 0 1;
geomTransf PDelta $IDGirdTransf 1 0 0;


set Ubig 1e10;

set MatTagUbig 100;
uniaxialMaterial Elastic $MatTagUbig $Ubig;


set SecTag1 1;
section Aggregator $SecTag1 $MatTagUbig P $MatTagUbig Vy $matID Mz;

# section Aggregator $SecTag1 $MatTagUbig P $MatTagUbig Vy $MatTagUbig Vz $matID Mz $matID My;

set LCol1 130.0

set Lp_c1 [expr 0.004*$LCol1];

set LBeam 91.0

set Lp_b2 [expr 0.004*$LBeam];


#################
### columns ###
#################

# Frame Y direction

element beamWithHinges 1 1 2 $SecTag1 $Lp_c1 $SecTag1 $Lp_c1 $Es $Acol_1 $Icol_1 $Izcol_1 $Gs $Jcol_1 $IDColTransf;


###############
### beams ###
###############

##### beams -- parallel to X-axis########

element beamWithHinges 10 11 12 $SecTag1 $Lp_b2 $SecTag1 $Lp_b2 $Es $Abeam_12 $Ibeam_12 $Izbeam_12 $Gs $Jbeam_12 $IDBeamTransf;


#################
### girders ###
#################

########## girders -- parallel to Z-axis####

element beamWithHinges 20 21 22 $SecTag1 $Lp_b2 $SecTag1 $Lp_b2 $Es $Abeam_11 $Ibeam_11 $Izbeam_11 $Gs $Jbeam_11 $IDGirdTransf;

Post Reply