Line load (Load)

Property	Value
Default Short Command	LL
Icon

Depending on the current FEM-Design module, constant or variable line force/moment can be defined easily by giving the load shape, direction and position. The load properties and definition tools are available on the tool palette of the Line load.

Figure: Tool palette of Line load

Definition steps

1. Select the load case from the load case drop-down list from Loads tabmenu, which you would like to add the new line load(s) to.
   
   If you have not defined a load case yet, you can also define and set at the  Default settings by giving a load case name. Here you can type any comment, which will be displayed next to the force.
   
   
   Figure: Load case definition
   
   The load will be displayed on the layer assigned to the selected load case and in the layer’s color.
2. Choose the load type:  Force or  Moment (FEM-Design module dependent).
3. Set the intensity values in the start (q1) and end point (q2) of the new load according to the current unit (that can be set at Settings > Units) in the tool palette or at  Default settings. If you inactivate the arrow (   ) next to the q1 field, you can type intensity value in q2 different from q1.
4. Define the direction of the force or moment axis (FEM-Design module dependent).
5. Choose a method for the action line definition (geometry).
6. Set the “intensity mode”, that means the connection between applied intensity and the action line at  Default settings, if the new load will be in skew position (not vertical or horizontal):
   • “Intensity meant along action line”
     The intensity will be meant along the action line, so the resultant will be calculated from the intensity and the length of the action line. Apply this option for dead load-type loads.
      
   • “Intensity meant perpendicular to direction of load”
     The intensity will be meant perpendicular to the load direction, so the resultant will be calculated from the intensity and the length of the horizontal projection of the action line. Apply this option for example to model snow load.
     
     Figure: Intensity difference at skew bars
7. Set the “direction mode”, that means the connection between applied load direction and the action line at  Default settings, if the new load will be a curved line load:
   • “Direction is constant along action line”
     The load direction set in the 4^th step will be constant along the action line.
   • “Direction varies along action line”
     The load direction will vary along the action line, so the characteristic direction set in the 4^th step will be taken into consideration in the middle point of the curved action line.
     
     Figure: Intensity difference at skew bars
8. Place the line load in the model view based on the chosen geometry method (5^th step).
   
   With the special tool called Object’s local system () you can add line load directly to a selected bar element in a direction set parallel with the one of the local system axis of the bar element. So, with this tool, you can merge 4^th, 5^th and 8^th steps to one step, if the required load direction is equal to the direction of the assigned bar element’s local axis.

Optional steps:

9. If the load is acting on the structure’s eccentric axis/surface select the Apply on the eccentric axis/surface option in the Default settings.
10. Modify the load properties (the host load case, intensity values, “intensity” and “direction mode”) with the  Properties tool of the Line load tool palette.
11. Modify the load direction with the editing tools (Editing Loads).
12. Set the display settings of the load (Load Display Settings).