Reactions
The Reactions analysis result shows reaction forces and moments in support structures under the current loading or analysis conditions. It represents how loads are transferred from the structure into supports such as point, line or surface supports.
Reactions are very similar to the Connection forces. While the Reactions are shown for support elements, Connection forces are shown for connection elements.
Reactions are available for several static and dynamic analysis contexts.
- Load cases – reactions from individual load cases
- Moving load maximum – envelope of maximum reactions due to moving loads
- Moving load influence line / surface – influence results for reactions
- Construction stages – reactions during staged construction
- Load combinations – reactions from defined load combinations
- Maximum of load combinations – envelope of reactions from multiple combinations
- Maximum of load groups – envelope of reactions grouped by load groups
- Seismic analysis – reaction response from seismic loading
- Time history – ground acceleration – time-dependent reactions from ground motion
- Time history – excitation force – time-dependent reactions from applied forces
- Periodic excitation – steady-state dynamic reaction response
Result selection
Depending on the selected analysis context, additional selections are required to display Reactions. One or more of the following parameters may need to be selected from the result lists:
- load case type, such as ultimate or quasi-permanent
- load case or load combination
- reaction component, for example force or moment direction, for envelope-type results
- construction stage
Only the selections relevant to the active analysis type are shown.
Result display
Reactions use a specialised result display that is fixed for this result type. The reactions are visualised using different graphical representations depending on the support type and reaction component:
These visualisations allow you to clearly interpret the magnitude, direction and distribution of reaction forces and moments in the support system.
Key characteristics of the display:
- straight thin arrows – reaction forces
- curved thin arrows – reaction moments
- straight double lined arrows - resultant forces
- curved double lined arrows - resultant moments
- 2D graphs – distributed reactions on line supports
- vivid colours – results on the positive direction of the axis (values are positive)
- muted colours – results on the negative direction of the axis (values are negative)
- grey colours – results for a single support (in contrast to a support group with multiple results in one object)