The introductory dialog
Inch-pound or metric
The dialog that first appears when the application is started offers a choice of three measurement unit systems:
- The inch pound system sometimes also called customary units. The maximum dimension is 320 inches or 26’ 8” and the resolution is 0.01 inch.
- Metric units with large dimensions. The maximum dimension is 32 metres and the resolution is 1 mm.
- Metric units with small dimensions. The maximum dimension is 3.200 metres and the resolution is 0.1 mm.
At any particular time the application works wholly with one system and there are no facilities for converting data from one system to another.
The choice of a unit system will cause the introductory dialog to be replaced by the main dialog where a new description of a cross-section can be input.
File open facility
With the introductory dialog the main menu Files “Open” item is enabled allowing the user to open a file of a previously prepared cross-section description. This also causes the introductory dialog to be replaced by the main dialog.
The main dialog
The main dialog has a traditional style main menu at the top with pull-down sub-menus.
The body of the dialog contains four list boxes where the names of various entities are displayed.
Across the bottom is a status bar where from time to time information is displayed.
Nothing on this dialog can be changed by the user. The lists are intended to allow the user to select an item. Facilities for various actions are provided in the menus.
Four kinds of entity and entity names
There are four kinds of entity; a material, a component, a load-case and a time affect set. Each entity has a name, determined by the user. The main dialog includes a list box for each entity kind where the entity names are listed.
Material: A material entity describes a material such as concrete, or mild steel.
Component: A component entity describes a part of the cross-section. Each component is either a shape component or a point component. Typically concrete is a shape component and an arrangement of steel bars is a point component.
Load–case: A Load-case entity describes a state of the cross-section that is of interest. Such states are such as the ultimate strength, the first yield of a mild steel bar or a given bending moment.
Time affect set: A Time affect set has provision for a shrinkage value and a creep coefficient for each component and the name of the load case that causes the creep.
Entity names can be up to twenty characters including spaces between words. The names can have practical meaning. The edit dialog for each entity kind includes a text edit box for the name and automatic facilities that ensure each name is unique within each entity kind.
The main menu has an item for each entity kind that includes “Add”, “Copy’, “Edit” and “Delete” menu items. The “Copy’, “Edit” and “Delete” require that an entity in the list is selected. A single click of a pointing device on an entity name will select it. A double click will have the same affect as the “Edit” menu item: it opens the editor for that entity. There is a known bug with this double click in that it does not always open the right entity.