MODELLING A CONCRETE FRAME USING STAAD PRO2000 2

[ERNESTOBARRERA]

i would like to know how to model a 3d multistory reinforced concrete building with two way reinforced concrete slab, using STAAD PRO2000. This must be done considering that the STAAD PRO2000 MASTER/SLAVE options yields wrong results, so it can't be used. The building of course is subjected to seismic lateral loads (response spectrum or equivalent lateral analysis), so the effects of story torsion must be taken into consideration.

Any advice and recomendations from you fellow structural engineers will be highly appreciated.

 

[v2]

you need ETABS.

 

[nevsam12]

I am not giving any help to you, but, I have a question to supplement your question. I am analyzing an existing concrete moment frame with shear wall on one side and rigid (floor) and flexible (roof) diaphragms. I plan to use STAADPRO 2000 also. In modelling, should I just use the concrete beams and columns, or do I need to also include "Finite Element Meshes" for floor slab and shear wall. Thanks for your response.

 

For analysis of shear walls subjected to lateral loads, your software needs to be able to analyze in-plane stiffness of the element/wall to resist loads on the edges. If StaadPro's shell element can properly handle in-plane stiffness, you're in business.

But if it's unable to consider in-plane stiffness, see if you can instead use beam elements (assuming the beam elements handle shear deformation), keeping in mind that beam elements may require rigid links between them if you model openings in the shear wall.

Same advice to use beam elements with rigid links for analysis of 2 way slab floor if the master/slave rigid diaphragm does not work and if shell elements cannot consider in-plane stiffness. For analysis of floors with lateral loads, you need to consider the in-plane stiffness of the floor which is usually near rigid relative to column stiffness.

If your master/slave rigid diaphagm does not work properly, you'll need to use an element which considers in-plane stiffness of your floor.

 

[rmonterroso]

Over the past months, I have been modelling a 27 story RC building with shear walls - columns - beams using STAAD.pro 2002 and am satisfied with the results. My structure is being modelled for UBC97 Zone 4 seismic loads (which STAAD is able to generate quite nicely, too).

I have used both the column - beam only simplification and then moved on to modelling the shear walls of the building using FEM technique, continuosly checking the results between one analysis and the other. Once satisfied that they were close enough, I have continued with the FEM only.

To address the issues you mentioned and were brought up by HILLBILLY, yes I am satisfied that STAAD is handling the in-plane stiffness properly.

By the way, I have NOT used the Master/Slave, but have kept a close watch on the deformations in my diafragms, both vertical and horizontal, finding them to be acceptable.

I would suggest 4 things:

1. Upgrade to STAAD.pro 2002. I have no experience with 2000, but from reading the postings of others and FAQs on their website, it seems they have improved many things in the last couple of years.

2. Browse in the "Research Engineers STAAD Products" FORUM for a lot of good info on STAAD.

3. Purchase the Research Engineers one year technical support package. I have bombarded them with questions and have found them to be very helpful in taking me from a complete novice to a pretty good user of their product in this time.

4. Read their manual, electronic help and the FAQ on their website. I have also found them to be quite useful. Their Example No. 9 in the electronic help (STAAD.pro 02 version) has an example of vertical RC shear wall. In migrating from the Beam-Stiff Beam-Col. analogy to Shear Wall, I used their example as a test case and modified its geometry and load conditions considerably, until satisfied I was getting reasonable answers. Then I used the technique to model the shear walls in my structure.

Rgds

PS. A proposito, habla usted español? Supuse que por su apellido es de descendencia latina. Creo haber visto su seudonimo en otros foros anteriormente. Saludos R. Monterroso.

 

We use Master/Slave in Spro 2001 and it works just fine. I haven't used Spro 2002, but there are several examples of master/slve to create a diaphragm effect. I would recommend upgrading. ETABS is too complicated to use.