Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering Transport Technology
A.A. Raksodewanto Stoten op staalkabels.
Masters thesis, Report 95.3.TT.4523, Transport Engineering and Logistics.
In chapter 3 of this report the test equipment is discussed, which can simulate the impacts on wire ropes, as these occur in practice and with which the acting impact forces can be recorded. During the entire process of the impact it is supposed, that the slack rope is suddenly pulled taut. Then first an increasing force occurs and next a decreasing force. The maximum value of this force is the impact force. After short time this peak load is followed by one or more of such peaks during the courses of the tensile load. Finally the mass of impact will perform a dying out vibration, at the moment the energy of the impact is assimilated. In this way the entire process of the impact is divided into two phases, an impact phase and a vibration phase.
The history of the wire rope is important, because the impact force of the rope shows an other behaviour with different histories. With these impact tests four different pre-treatments are applied, before the ropes are loaded with impacts. The four starting conditions of the rope are:
1. Not pretreated. This condition occurs in practice with new wire ropes.
2. Repeatedly bent up till 9000 bends on the REFMA, what is comparable with a rope, which is used under low loads, during a few time. 3. Pulsated with 3000 load cycles between 25 kN and 33 kN. This is comparable to longer use under heavy loads, but still in the safe time of use. 4. Pulsated (3000 cycles with between 25 kN and 33 kN) plus repeatedly being bent (15000 bends). This can be considered to be comparable to a
wire rope, which is so often used with heavy loads, that the rope is at the end of his period of safe use.
Thery on behaviour of steel wire ropes which are exposed to impacts, depending on his is described in chapter four of the report. The influence of the impacts on the wire rope endurance is discussed as well.
In chapter five the results of the experiments are compared with different theoretical concepts.
In chapter six the influence of the impacts on the elasticity of the wire rope is discussed based the results of the experiments. In this chapter also the damping factors are discussed, which could be derived from the results of the experimentd.
Chapter seven deals with the conclusions of the research. Reports on Transport Engineering and Logistics (in Dutch)
