SAP vs ETABS for Towers 5

[strucengr]

We have a couple of airport control towers to be analyzed. They might be either precast concrete, concrete shearwall or steel moment/braced frames from 90 to 150 feet in height and a small footprint of a few hundred square foot. There will not be regular floors in between except a flexible stair or elevator core.

Which would be a suitable software - ETABS or SAP2000? I know SAP200 is quite advanced to do this kind of project but ETABS might be useful for future regular building projects. Instead of shelling our a few grand for both, can we get by with just one software.
1.My main question is if ETABS can handle such a project.
2. If ETABS is used, what are its limitations on such a structure?
3. I believe the analysis engine is the same for both.
4. Is ETABS more dependent of story heights?
5. What would be the limitations in SAP, if any?

Thank you and I appreciate your response.

 

[stressed]

strucengr, here are a few observations which may help you,

1. From the info. you've given, ETABS should be able to handle the design and analysis of your airport control towers no problem

2. No real limitations, just a couple of considerations to keep in mind.. ETABS keeps track of the model on a story by story basis. At each story, ETABS will break up columns and report output on story by story basis. In your case, you can make one tall story and add reference planes (vertical gridlines between stories), or you can have variable story heights, depending on what you are trying to do. I think SAP is little friendlier in adding and modifying gridlines, but no great advantage there

3. For the most part, I believe you're correct. Modeling features between ETABS and SAP are very similar..nearly identical. But there do seem to be some differences in analytical capabilities. ETABS does not offer solid finite elements which is usually not a big deal, only has shell and frame elements, and ETABS pushover analysis is limited to static loading.. whereas SAP has solid finite elements and can handle pushover analysis under static and/or time history loadings. SAP offers post tension modeling, ETABS does not. Maybe CSI will add these capabilities to a future version of ETABS, or maybe you don't need those capabilities for your project requirements.. either way, those are a few considerations you need to be aware of before deciding.

4. As I mentioned before, ETABS keeps track of the model based on stories. In a building system it's great to get story shears, beams and columns reported by story, use 'similar stories' to make changes, etc.. in other structures it makes modeling a little more of a hassle

5. The big advantage ETABS offers for the project you described is shear wall design, which is not available in SAP. Also, ETABS offers design of composite beam floors which is not in SAP. ETABS auto-meshing of floors is not available in SAP either. ETABS auto-meshing of floors is a time saver in some designs, but doesn't work so well in very irregular structures in my experience

my $.02