One of the unique features of Scia Engineer is, that every project regardless license setup is able to handle more representations of the same model. These model representations are are present as view parameter - they just represents different view on the same object. Based on that, one object can have more representations, and there are various types of them.
This is brief summary of all available options in current Scia Engineer 2010 version.
3D volumetric representation of any object. In Scia Engineer terminology called General Solid, and it can exist in one of 3 states – Correct General Solid, Open Shell or General object. General solids are not used for any kind of analysis.
Represents real physical shape, a virtual Building Information Model of the structure. Might contain load bearing and not load bearing parts. Exact member geometry can be used in analysis model as well, to define exact position of steel connections or reinforcement bars which are not used for code check, but only for visualization and Bill of Material.
Analysis model which is used for FEM analysis, design and checks is always fictive and simplified representation of real structure. Some of the rules are based on code or well known empiric rules, but generally, this is the point where qualified structural engineer is taking decisions. Simplified model has to represent real structure behavior, but also needs to provide results asked for certain type of analysis or code design with reasonable efficiency.
Some typical engineering decisions can be : whether to create 1D or 2D analysis member from certain 3D solid object,different fictive members not present in structural model, mesh size and type, different model data like hinges, rigid arms, supports, eccentricities definitions etc.
FEM model is numerical representation of Analysis model. FEM model contains only mesh nodes with appropriate data, which are needed to solve stiffness matrix according to FEM theory and selected solver type.