Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering Transport Technology
R.J.M. Olierook Dynamische demper tegen "skew" van een container. Computer program, Report 99.3.TT.5170, Transport Engineering and Logistics.
Due to the expected strong growth of the transfer of containers in the harbour of Rotterdam, higher requirements are set for the transfer capacity of the cranes. The new generation of sea vessels will be bigger than the currently used vessels. Despite the bigger size of the sea vessels, they must be loaded and unloaded in the same time as the current vessels are loaded and unloaded. This results in higher demand of the transfer capacity. In order to achieve this higher capacity, the load control is seen as the main tool to decrease the transfer time. Filtering of unwanted movements results in a higher transfer capacity. In this report an analysis is presented of the application of a dynamical vibration absorber on a spreader, in order to reduce the 'skew' of the container during transfer ('skew' = horizontal rotation of the container around its vertical axle). This movement is hardly absorbed by the current system and will oscillate for a relative long time due to unequal cable length or external forces.
The variable behaviour of the system and low frequency for the 'skew' movement are important factors for determining the dynamical vibration absorber. Every loaded container got its specific features as weight and inertia and the dynamic behaviour is therefore different for each container. In this report, the dynamic vibration absorber will be designed for a container with a weight of 12.000 kg, which causes most 'skew' according to experiences in practice. The behaviour of the container in relation with the 'skew' movement can be manipulated in a positive way by applying a dynamical vibration absorber. Especially when a forced vibration is concerned (during transfer in combination with unequal cable length), a dynamical vibration absorber performs very well. When an actuator is applied to the dynamical vibration absorber, the 'skew' movement can even be reduced between the limits in order to position the container on a vessel or AGV (Automatic Guided Vehicle).
Reports on Transport Engineering and Logistics (in Dutch)
