The Reactions form has the following areas:
Load Case/Load Combination drop-down lists. Choose the load case, load combination, or modal case whose support or spring reactions is to be displayed.
Load Case option. The support or spring reactions for any of the following can be plotted assuming that the type of load case has been defined in the model.
Static load case (linear) option.
When the Tabulated option is selected, the force values are displayed.
When the arrows options is selected, the arrows indicate the direction of the force acting from the support (spring) on to the elements connected to the support (spring).
Response spectrum case option. The reaction values are displayed along with arrows showing the direction of the force. The arrows indicate the direction of the force acting from the support (spring) on to the elements connected to the support (spring). Note that the response spectrum reaction show the maximum value obtained for each component of each reaction and also note that the values may not occur at the same time in an earthquake.
Time history case option. When a time history case is chosen, use the edit box to specify the time step in the time history analysis to be plotted. If a time that is specified is before the time history starts, the first step of the time history is displayed. If a time is specified that is after the time history finishes, the last step of the time history is displayed. If a time is specified that is not exactly the same as one of the output time step times, the nearest time step is displayed. The reaction values are displayed along with arrows showing the direction of the force. The arrows indicate the direction of the force acting from the support (spring) on to the elements connected to the support (spring).
Static nonlinear case option. When a static nonlinear case is chosen, use the edit box to specify the step in the static nonlinear analysis to be plotted. The reaction values are displayed along with arrows showing the direction of the force. The arrows indicate the direction of the force acting from the support (spring) onto the elements connected to the support (spring). Use the following steps to get an idea of the force and deformation associated with any step in the pushover:
Click the Display menu > Static Pushover Curve command to access the Pushover Curve - Case {Name} form.
Click the File menu at the top of the form.
Click the Display Tables command to display a table that, among other things, includes the force and deformation for each step of the nonlinear static analysis.
Load combination option. Choose to display reactions for the load absolute maximum, maximum or minimum. Depending on the Plot Type option selected, the reactions can be displayed using arrows showing the direction of the force. The arrows indicate the direction of the force acting from the support (spring) onto the elements connected to the support (spring). If a load combination is a single-valued load combination, its reaction values are displayed. If a load combination is multi-valued, the displayed results are those with the largest absolute value. For example, if the minimum value at point 1 is -3 and the maximum value is +2, the -3 value is displayed. If an adjacent point has a minimum value of -1 and a maximum value of +2, then +2 is displayed at that point. This process continues for every component at every reaction point.
Modal Case option. When the Modal Case option is selected, choose the mode number for which reactions are to be displayed.
Plot Type options. Choose to display the reactions using Arrows or as Tabulated values.
Display Result for These Components. Choose which reactions are to be displayed. The components are assumed to be self-explanatory. If more information is required, please consult the code-specific design manuals (Help menu > Documentation command).
Click the Apply button to update the active window. When the Apply button is used, the Reactions form will remain open until the Close button is clicked. This allows another selection to be made on the form to review multiple displays without using the command to recall the form. If only one Plot Type or Component is to be displayed, the OK button can be used to both update the active window and close the form.
Access the Reactions form as follows:
Run an analysis.
Click the Display menu > Forces/Stresses Diagram > Support/Spring Reactions command.