Analysis Case Definition
The case description definition dialog is made available when an analysis case definition is required, it is not invoked directly.
The case description definition dialog is made available when an analysis case definition is required, it is not invoked directly.
Analysis cases are one of the basic concepts that needs to be understood for anything other than a linear static analysis. It is important to understand the difference between a load case and analysis case. This is best achieved by using an example.
Where relevant, tables are output for those items identified in the case, node, element and member lists. Changing a list from the default to a specific selection refines the content of the table.
Case descriptions are used to store commonly used case descriptions. For example, the dead load may have contributions from several load cases. The combination of the loads can be entered as a case description and this can then be used when a case is required in an analysis task.
The case list for a Graphic view can be specified both in the Graphic settings dialog box and via the Lists toolbar. The full GSA list syntax is available when specifying the list.
Once a model is set up the user then wants to analyse the model. Before analysing the user should have a clear idea of the differences between load cases, analysis cases and combination cases. For anything other than simple linear static analysis it is also useful to have some idea of the relationship between analysis cases and analysis tasks.
Combination cases are similar to analysis cases but differ in two respects:
It is often useful to combine results from more than one analysis case. This is achieved by defining combination cases, which combine a number of factored analysis cases (e.g. 1.4A1 + 0.8A3).
Once analysis has been carried out GSA can then proceed to member design. The Design task wizard allows you to automate section design and RC member reinforcement design. The design wizard can be activated by:
When loads are applied to the model they are assigned to a load case. Load cases should be assigned to simplify the management of the data. Load cases, when referred to in lists, are prefixed with an “L” (e.g. L2). See Lists for more details.
Loading is applied in load cases, so load cases are a convenient way of grouping together a collection of loads that are to be considered together. Thus a load case may be set up to contain all the loads associated with dead loads, another to contain all the loads associated with live loads etc.
In output tables that include an entity number and a case number per line, the default sequence of lines is output in ascending order.
Combination cases may be used to combine the factored results of a number of analysis and combination cases. They may also be used to identify a number of permutations of factored cases for the enveloping of results. The former are referred to as simple combination cases and the latter as enveloping combination cases.