Line Loads

Line loads are specified in kN/m and are positioned using Load Points. The Load groups and Load number are set using the Load Group drop down options and the load direction is controls by specifying the Load Direction drop down. Line load can also be used to apply loads normal to the line itself, which represent a line load acting in the plane of the FE surface, using the M(In Plane Normal to line) option. The W (Y Global Full Length) option allows vertical loads to be applied even if the FE surface is itself oriented vertically. 

Defining Moments with FE Line Loads

Line loads can be used to define a moment acting over a line, where the rotation is about the line axis. This is achieved using the R(Moment about line axis) load direction.

The R load is 'about' the axis of the line the load is drawn on. Think of it as something you might use to create a cantilever moment on a slab edge. Because it's about the axis of the line, the direction the line is drawn in influences the direction of the moment. The moment will be counter clockwise as you look down the line from the start end.

Line load intensity can be linearly varied by inputting a start and finish value, separated by commas.

The position, shape and extent of the line load is controlled by the input load points. The first Load point in the list is the start point, while the last input load point is the end of the line load. The order load points are put in will control the intensity of the load where the line load is varying.

When inputting load points, the LP's can be input manually by typing the required values into the Load Point input, with the LP number separated by commas. Load Points can also be selected graphically. On selecting the Load Points input, then clicking on the  icons, this will open a small "Pick Points" pop-up window. Now, using the mouse pointer and left clicking with the mouse, the individual load points can be picked - each selected Load Point No. will appear in the small window. To finish, click on the  icon.

An example line load has been set up in the following screen capture. Line loads can be used to form closed or open boundaries. Line loads can also cross over each other. It is also possible to assign multiple line loads to coexist between common Load Points. For example, Dead and Live loads can be defined on the same lines using multiple line loads, each assigned as a separate line loads.