Before doing the checks, it is necessary to enter basic design data such as effective length, grade of steel etc. This information can either be entered in the Frame, Load or Plot windows by selecting design members and using the commands under the Design menu, or it can be entered in tabular form in the Data window. The actual design parameters that can be changed by the user will vary according to the current design code. A list of design variables and their default values are described in subsequent chapters in this manual.
Although most of the design variables are pre-set to the most commonly used values, you will probably want to enter the design information for at least some of the members in the frame that you wish to check. You set design variables by selecting the members you wish to change and then choosing the appropriate command from the Design menu.
It is not necessary to enter the design data for all of the design checks. Usually you will want to check some members for bending, others for compression and so on. The items under the Design menu help you enter just the required information depending on what type of check you are doing. The design properties are grouped according the categories described above and the items in the Design menu reflect these groupings. The dialogs displayed by each of these commands will vary according the current design code.
When performing a bending check, you may need to specify a number of properties relating to the unbraced length, location and type of lateral restraints, and the stiffener spacing on the member.
Tension checks usually require the user to specify the area of holes in the cross section and a coefficient to account for the distribution of end forces or used to computing effective net area of the section.
When checking or designing members for compression, it is necessary to specify the effective length and unbraced length of the member.
Some design codes require the user to specify a coefficient that accounts for the distribution of moments along a member.
With some design codes, it may be necessary to specify the deflection limits used in checking the serviceability of a member.
Some design codes require a member to be categorised according to the required ductility of the member.
For some design codes, no design data is required for the design checks in a particular category and so the menu item will not be enabled. In other codes, there are no design checks performed within a particular category and the menu item will again be disabled.