2.2 Sets of Lines

This module window manages the geometry parameters of the movable loads. It is possible to define different paths.

Moving loads are generated along lines. Hence, it is favorable if "guiding lines" for these loads are already available in the RFEM model.

A set of lines contains one or several lines describing the moving direction of the movable load. The number of the first set of lines is preset. The description Set 1 can be overwritten manually.

If loads are moving parallel or with offset on surfaces, you should create another set of lines with the [New] button. Thus, an individual control of moving loads is possible in a set of movements (see chapter 2.4).

The buttons in this window section have the following functions:

Table 2.1 Buttons for managing sets of lines

Button	Function
	Goes to previous or next set of lines
	Creates a new set of lines
	Allows for renumbering current set of lines
	Deletes current set of lines
	Deletes all sets of lines without any warning

In the input field, you can enter the numbers of the lines representing "guiding lines" for the moving load.

The order of the numbers specifies the moving direction.

Use the  button to select the lines graphically in the RFEM work window. Again, make sure that you click the lines in the right order: The order defines the moving direction.

Clicking the button reverses the order of the lines. Then, the moving loads will run the set of lines in the opposite direction.

The total length of the set of lines is displayed in the Parameters section (see below).

This window section manages general settings for the generation of load cases.

To adjust the units of length, select on the menu Settings → Units and Decimal Places (see chapter 5.1).

The moving step Δ controls the (equal) distances by which the loads move over the surfaces. The smaller the moving step is, the more load cases are created.

The total length of lines existing in the current set of lines is displayed for information.

The load generation starts at the initial node of the first line in the set of lines and ends at the end node of the last line.

With the input fields Offset at start and Offset at end you can shift the starting point or end point of the moving load. The offset a_A describes the distance of the first load position to the initial node of the first line.

Only positive distances as shown in the sketch are allowed for an offset. In order to model a load entering the runway, you can define moving loads having negative x-locations (see chapter 2.3).

This input field allows you to arrange loads beside the moving line. So you can use, for example, a surface's border line as a reference, defining a new line in RFEM is not necessary. Then, moving loads will move parallel to the lines of the set of lines in a distance of e_y.

The following sign rules are applied: The direction of the set of lines is specified by the start and end nodes. In viewing direction, positive e_y values arrange loads to the right of the moving line, negative ones to the left.

As an alternative for offsets (see above) you can define bumper zones which are kept free of loads. Bumpers are relevant for crane runway beams and structural systems with lateral boundaries. Moving loads with negative x-locations, for example, will then be shifted until they do not extend any longer into the Bumper at start.

The input fields b_A and b_B allow for defining load-free areas for the start and end of the set of lines.