In the Settings & Options tab, you can adjust the value for the acceleration of gravity, the geometric tolerances of objects, and the alignment of axes.
Settings
In this section, you can check the value of the "Acceleration of gravity" g. It is used to determine the self-weight of members and surfaces, to convert masses (“mass conversion constant”) and for dynamic analyses. The default value is 10.00 m/s², which you can adjust, if necessary.
The “Orientation to North” describes the location of the model in relation to the main compass direction. A north orientation of 0° is preset, which corresponds to a north orientation along the global X-axis. If you want to change the orientation of the model, select the check box and enter the angle Φ.
Model Tolerances
When modeling or importing data from a CAD program, slight geometric differences may occur in the model objects. RSTAB corrects these inconsistencies automatically if particular distances fall below the "Tolerance" text boxes. Thus, nodes located very close to each other will be combined, members located outside of planes will be integrated into the respective planes, or minimally inclined members will be classified as vertical.
The preset tolerances are suitable for most models. In the case of small model dimensions, it may be necessary to adjust the tolerances accordingly.
Options
In this dialog section, you can decide whether you want to apply "representatives" for members and sets of members in the model. By activating the "Member Representatives" and "Member Set Representatives" check boxes, the corresponding tabs are added to the dialog box. They are described in the chapters Member Representative Wizard and Member Set Representative Wizard.
The “Activate Rule-Based Link Generator” list opens the option to use a generator to link unconnected model objects. This feature is described in the chapter Rule-Based Link Generator . Use the
button to create a new generator and the
button to edit the entry selected in the list.
Global Axes XYZ
This dialog section controls the orientation of the global axis Z. In CAD programs, the Z-axis is usually directed upwards, and downwards in structural analysis programs. This is irrelevant to the calculation.
If Z is directed upwards, the factor -1.0 is automatically applied in Z for the "Active self-weight" function in the load case (see the chapter Load Cases ).
Local Axes xyz
The descriptions of the member axes are regulated differently in the standards. In this dialog section, you can define how the principal member axes z or y, as well as the surface axis z, are oriented in order to adapt the local axis systems to the regional conventions.
The positions of the local member axes are illustrated in the dialog graphic.
