TUTORIAL
(This is actually Chapter 5)
5.1 General
This user manual describes the use of 2-D Truss designer’s fully complete module assuming the installed directory is the default directory and Internet Explorer Ver.4.0 or above was completely installed in the machine.
Type "r" at the command prompt. Then a window will appear as follows;
Fig5.1.1 Main window
This implements standard windows menu such as File menu, View menu etc. If the new structure model has to be created, then choose the File menu and then New. Truss Designer will prompt the user a modal dialog box as shown below,
Fig.5.1.2 Create new file dialog box
In this total number of nodes and members in the truss, which is going to be analyzed has to be given and the space needed for the structure should be also, selected.
Then press the "Ok" button to dismiss the dialog box. Now select "Modify Structure" and then "Add nodes". Following dialog will appear.
Fig.5.1.3 Add nodes dialog box
Enter the node number and other data in specified text boxes and press "AddPoint" button to tell the Truss Designer the coordinates of the particular nodes. To verify the data input Truss Designer will list all the entered nodes in the list box in the left side of the dialog box. In order to enhance the user friendliness of this module graphical input feature also included. As user has enabled Add Nodes dialog box module will be ready for both graphical and alphanumeric inputs. Therefore as user moves the mouse around the view panel coordinates of the mouse cursor will be displayed in the text boxes. As user clicks the mouse, module will assign the node number and corresponding coordinates also.
N.B.: Node number is assigned automatically increased with the mouse clicks.
Fig.5.1.4 Graphical input of nodes
In order to ease the mouse input current position of the mouse cursor will be updated in the "AddNodes" dialog box.
After adding all the nodes, Member properties dialog box can be loaded by selecting "Add/Change members" menu item in the "Modify structure" dialog box. This is also similar to "Add Nodes" dialog box and has same functionality. It also has standard member sections list in lower left-hand corner. Since this software is capable of handling large number of members another feature for multiple selection is also added in this dialog box. By enabling multiple selection dialog box user can select multiple members at once and then assign them a particular section from standard section list box. It should be noted that when adding external members double angle check box also should be checked before selecting member in order to assign double angle sections. After finishing all the input click "Ok" button to dismiss the dialog box from the screen.
Fig.5.1.5 Add/change members dialog box
Fig.5.1.6 Display of input data graphically and in tabular form
(Note that double angle member numbers are displayed with letter D to distinguish them from other members)
Now select "addres" menu item from "Force and restraints" menu to load the Restraints and force dialog box. In this dialog box user has to input forces at the nodes and boundary conditions. This can be done either as mouse input or alpha numerically, as in above cases.
Fig.5.1.7 Modify or add restraints dialog box
After assigning all the sectional properties and the boundary conditions user can proceed to analysis part of the program. By selecting menu item force combinations, Force combination dialog box can be loaded into the memory. In this, three load combinations according to BS[7], will be applied to the model and axial loads and displacements will be calculated accordingly. Then all five loading combinations will be calculated and the design force will be determined for each member. Those design forces will be displayed in the list box, after pressing calculate five-combination button, as shown below in Fig.5.1.9. At the same time deflected shape will be shown in the main window graphically (Fig.5.1.10)
Fig.5.1.8 Graphical display of the loading arrangement
Fig.5.1.9 Automated load combination dialog box
Fig.5.1.10 Graphical display of deflected shape for automated windward Load combination
Fig.5.1.11 Graphical display of deformed shape under automated vertical Load combination and alphanumeric display of design forces
Fig.5.1.12 Display of the member check results
Furthermore in order to make the software more user friendly some additional features are also provided. They are,