FL 111 represents a simple bar structure. In the single plane system the bars are only subjected to compression and tension. Loads are applied only to the nodes.
  The unit comprises three members that are joined together using discs such that the joints are free to move. A longitudinally adjustable bar permits the bar structure to be constructed with different angles. The bars engage in the discs by snap-locks. Two of the node discs also form the supports (fixed and free) and are clamped to the sturdy aluminium section base frame. The external load is applied to the upper nodal point by means of weights.
  The bar forces occurring are measured by the deformation of leaf spring elements in the middle of the bar. The method of joints enables the bar forces to be determined by formulating a system of equations.

- Measurement of bar forces
- Calculation of bar forces by the method of joints
- Comparison: measurement result - calculation - graphical method