Gable frame

[HoshangMustafa]

Hi

I'm trying to model a gable frame. I wish if u could follow me step by step. The attached file is the dwg & rtd for the project.

Best regards

[Rafal.Gaweda]

screen shot in message 11

http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Non-linear-analysis-P-delta-analysis/td-p/36...

Use offsets to set sections properly or leave it as it is.

[HoshangMustafa]

Hi

Plz find the attached file. Is it OK?

[HoshangMustafa]

Hi

Plz find the attached file. In this stage the releases are set for the purlins. Is it OK?

[Rafal.Gaweda]

Purlins not connected with roof - at all.

[HoshangMustafa]

Hi

Plz find the attached file. Is it OK till now?

[Rafal.Gaweda]

Is there any difference between these models?

This is what I see:

[HoshangMustafa]

Hi

Should I delete all these purlins and redraw them or there is a simple way?

[Rafal.Gaweda]

Why not to move them to correct location?

[HoshangMustafa]

Hi

Thanx RG

Plz find the attached file. I moved the purlins to the correct locations. If it is OK, I'll step forward to the next stage.

[Rafal.Gaweda]

Supports missing

[HoshangMustafa]

Hi

Thanx Rafal

Find the attached file. I appreciate if any notes.

[HoshangMustafa]

Hi

Plz find the attached file with the dead, live & wind loads applied.

[Rafal.Gaweda]

And ?

It seems to be OK - no errors, no warnings, no instabilities

[legar]

To HoshangMustafa:

For first trial - seems to be OK.

Next:

1. First step - correct cross sections after national code checking.

2. Correct geometry so external steel flanges will be parallell to wall and roof slopes.

3. Check if frame is sensitive to buckling in a sway mode. There are many buckling forms, Eurocode generally requires to use the 1-st which is (in most cases) critical for portal frames. As the buckling form itself is just a vector, without real magnitudes, a scaling factor is needed to transform the form into real imperfection. The scaling factor is taken equal to the magnitude of initial sway imperfection.

Look at http://forums.autodesk.com/t5/Autodesk-Robot-Structural/Non-linear-analysis-P-delta-analysis/td-p/36...

message 10 & 11

4. Calculation run - correct sections if needed or end if results are satisfied.

BTW

If you want to optimize sections as much as possible, you should take into design Joint edge internal forces:

eg. for Knee:

eg. for internal column:

and so on...

JC-Legar

[HoshangMustafa]

Hi

Plz find the attached files. How can I solve these problems? Am I doing correct with the dead, live, wind &thermal loads? Am I correct with the combinations? How can I make these bars solved by ARSA itself (i.e making ARSA choose the best section from its database).

[legar]

You didn't specify SLS limits for some bars (Girts).

JC - Legar