## Beam-Column joint modeling in SAP2000

## Beam-Column joint modeling in SAP2000

(OP)

Hi everyone!

Maybe this is easy, but it's giving me some trouble. My intent is to model a 2D beam-column joint so as to have the continuous beam only propped by the column, with no bending moment transission from one ement to the other. Both beam and column are continued across the joint, i.e. the node is an internal one to the structure.

Thank you in advance for any help provided.

Maybe this is easy, but it's giving me some trouble. My intent is to model a 2D beam-column joint so as to have the continuous beam only propped by the column, with no bending moment transission from one ement to the other. Both beam and column are continued across the joint, i.e. the node is an internal one to the structure.

Thank you in advance for any help provided.

## RE: Beam-Column joint modeling in SAP2000

BA

## RE: Beam-Column joint modeling in SAP2000

My question is more relative to the software usage than the design issue itself.

## RE: Beam-Column joint modeling in SAP2000

You can model a structure with a continuous beam and column, intersecting at a joint. The beam can be specified to be pin connected to the column at that joint by giving it freedom to rotate but not to translate relative to the column.

To build that structure requires either a double column or a double beam, as it is not possible to have the beam running through the column without transmitting a moment.

BA

## RE: Beam-Column joint modeling in SAP2000

https://wiki.csiamerica.com/display/tutorials/Mode...

Thank you again for the time You dedicated to answering my question.

## RE: Beam-Column joint modeling in SAP2000

1. The structure in Fig. 1 cannot be built as shown, without introducing eccentric moments because members are not aligned. If you are planning to use I-beams, the eccentricity will be equal to the width of flange. Bending moments or torsional moments will exist in some members (and I-beams are not noted for their torsional resistance). It is not readily apparent how the eccentricities can be avoided, but I expect it can be done using double members.

2. The vertical reaction at B is 100kN by inspection, so the moment at E is clearly 300kN-m in both member BED and CEF (where F is the end of cantilever).

3. Step 7 should read "

Assign a pin support to joint 1, and a roller support to joint 5, not 2"It would not have occurred to me to use four joints at Point E. I was thinking of two joints, one connecting BE to ED, the other connecting CE to EF. That would require one more member connecting the two joints with translation prevented but rotation permitted.

BA

## RE: Beam-Column joint modeling in SAP2000

The real structure would certainly be affected by the presence of eccentric moments, unless use is made of coupled members (as You said). In my case, the analysis gives good results thanks to the fact that I can restrict it to the 2D plane. The bending moments You envisage are the right ones and, should You wish to do it, You could also go about downloading the entire SAP model at the same link I left in my previous reply (go to the bottom of page). I double-checked it by hand computation and everything seems to work correctly.

## RE: Beam-Column joint modeling in SAP2000

BA