Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering Transport Technology
M.J. Poot Het praktisch toepassen van staalsoorten met hoge rekgrens: ontwerp van een bovenarm van een lemniscaatkraan. Masters thesis, Report 96.3.TT.4784, Transport Engineering and Logistics.
FIGEE is developping a lemniscate crane for mobile use on the quay. To keep the load on the quay as low as possible, especially the upper arm has to be designed with a lower weight. The loading condition seems to be suitable for using high strength steel.
This report shows the possibility and rules for design for using high strength steel according to the Dutch regulations for the design of hoisting appliances. A few kinds of high strength steel are allowed to be used.
The permissible static load will be higher with increasing yield strength. Less material can be used, however, the stiffeness of the construction will decrease. Therefore, thinner material has to be placed further away from the neutral axis. This will cause decreasing of the slenderness ratio.
The permissible stresses due to crippling, especially for bars with a small slenderness ratio, and buckling, are higher with increasing yield strength. When there are acting highly dynamical loads, the fatigue stress will hardly be higher in comparisson with 'normal' steel.
For the upper arm a design is made in which high strength steel has been used. In comparisson with the old upper arm, there has been a big reduction in mass. Also the mass of the balancing mechanism can be reduced. Each ton reduction in the upper arm will cause a reduction of about 2,8 tonnes for the total crane.
Reports on Transport Engineering and Logistics (in Dutch)
