ETABS vs RAM

[noma]

We have been using ETABS for a couple years - I find it to be a "buggy" program - I spend a lot of time messing with fixity at various points to get rid of errors, etc.

We had a RAM presentation yesterday - It seems to be an "easier" program to use - though I don't think it has the same capabilities as ETABs.

Does anyone have enough experience with both to make an impartial comparison, listing pros, cons, etc?

TIA

 

[alexbzeta]

We use both ETABS and RAM, and our office designs concrete and steel buildings anywhere from 1 to 60 stories.

RAM can be much more productive because it makes a distinction between gravity and lateral members, and only models lateral members as finite element. Everything else is simple beam and statically determinate. This makes the model run much faster and schematic studies are easier to carry out. RAM also does a much better job implementing code provisions.

That being said, ETABS definitely has better analysis capabilities. We tend to stick with RAM unless we are forced into ETABS due to analysis constraints. For example, two-way slabs, sloping columns, cantilevers without backspans, and hangers cannot be easily modeled (there's messy work-arounds for these items). Also, no time history, push-over analysis, or nonlinear elements (i.e. dampers) in RAM. The column module (non-FEM) does give nice take-down loads based on tributary area which you cannot do easily in ETABS because of slab or bracing FEM behavior.

Lastly, RAM does not play well with REVIT. I haven't tried ETABS and REVIT, but it can't be much worse.

 

[prsconsultant]

Completely agree with alexbzeta.

Few other advantages of RAM are: If you are designing concrete frame structures RAM has the capability of generating beam & column schedules.

RAM has incorporated all the seismic requirements in to their steel design module, where as ETABS is lagging in this area.

ETABS works better than RAM with REVIT.