Dynamics: Pendulum Systems

Static behaviour of an outward inclined suspended system

This demonstration shows that an outward inclinely suspended system is a mechanism that moves sideway if a vertical load is applied asymmetrically on the plate.

    
(a)                                                                                (b)
Fig. 14-8: Static behaviour of of an outward inclined suspended system

Consider two suspended systems, where a steel plate is suspended by two vertical strings and the same plate is suspended by two symmetrically outward inclined strings, as shown in Fig. 14-8.

Place similar weights asymmetrically on the two plates as shown in Figure 14.8b. It can be observed that the vertically suspended system does not experience any lateral movement while the outward inclinely suspended system undergoes both lateral and rotational movements.

For the vertically suspended system, the vertical and lateral movements are independent and the vertical load only induces vertical deformations of the strings with little rotation due to the difference of the elastic elongation of the strings. For the plate suspended by the two outward inclined strings, the horizontal and rotational movements of the plate are coupled. The movements relate to the geometry of the system rather than the elastic elongation of the strings.