# General Specification
This can be accessed from the Data explorer or from the “Model | Data Modules | Specification | General Specification” menu command. The analysis specification gives information about the analysis model as a whole.
# Definition
Structure Type & Global Restraints
The structure type describes the type of structural model to be considered. The options are
- Space – 3D structure type. This is the most general structure type, and all the others can be considered as subsets of this.
- Plane stress – 2D analysis option with plane stress conditions.
- Plane strain – 2D analysis option with plane strain conditions.
- Axisymmetric – 2D analysis option with axisymmetric conditions.
Global restraints are applied to all the nodes in a model, e.g. to model a plane frame in the XY plane, the user should select a space structure type and apply global restraints in the Z translational, and X and Y rotational, directions. Global restraints do not need to be specified for directions with implied restraint due to the structure type. These directions are displayed greyed. In previous versions of GSA there were also 'Plane' and 'Grid' structure types. These are no longer supported but it is straightforward to set up the appropriate global restraints.
Edge Load Specification
It can be convenient to describe edge loads as pressures or as force per unit length.
Tolerances
There are a number of options in GSA that depend on setting appropriate tolerances that apply to the whole model.
Units
A base set of units can be selected for the model. These become the default set of units for tables and graphical views. The current units are displayed in the “Units” group box.
Currency
Currencies are stored using the ISO 4217 currency codes (e.g. GBP for United Kingdom pounds or USD for United States Dollars). The currency can be changed to any of those supported by GSA or none.