The basic difference between ETABS and SAP2000 is that former is special purpose software while the later is general purpose.
Special purpose softwares are designed for specific use, ie, ETABS is for building systems, it has all the necessary tools for building systems, as well as help in geometry formation of building systems.
On the other hand SAP2000 is a general purpose, that is, you can model any kind of geometry in that and do the analysis and design.
Both of them have the same analysis engine at core.
ETABS:
- This program is most utilized for handling large scale seismic (or wind) projects, including those that involve Non-Linear modeling.
- It is mostly used for Multi Storey/ High Rise buildings. High end analysis applications for such structures: Time dependent material properties like creep and shrinkage, construction stage analysis, Column shortening Analysis can be performed.
- It allows for more simplified modeling of the entire structure, enabling the designer to focus on macroscopic performance targets
- It is well equipped to handle simplified lateral procedures, Push-over analysis, Response Spectrum Analysis, and Response History Analysis.
- The data output options are much more conducive to lateral design
SAP2000:
- It is primarily used for gravity analysis and design
- It is often utilized for smaller structures, or portions of a larger structure.
- It is great at handling complex geometry as it offers users a lot of different element types and a lot of customization with regards to meshing options.
- It is used for all types of general structures like stadiums, water retaining tanks, airport hangers, chimneys etc., It has predefined templates for the ease of modelling such complicated structures.
- It can also be used for wind analysis and for more simplified seismic design procedures. However, it will take more data post-processing to retrieve the desired results for story drift, story shear, base shear etc.
- It lacks some of the simplicity that ETABS has of discretizing the structure into macroscopic elements.
Please note that there are likely are some finer points regarding the differences between each program in regards to the analysis engine and solver. This is something only some folks from Computers & Structures Inc (the manufacturer) can answer.
