Use of balancing rope for damping of cargo sways moved by a loading crane

Abstract

It has been proposed to add a load-lifting crane with a flexible cable suspension of cargo with an additional side balancing cable. The latter is located predominantly horizontally. An additional rope is attached to the boom, and is also fastened by the unit to the main cargo cable at its intermediate point between the boom tip and the load handler. It does not require the addition of a drive drum with a cable winch with a rotary damping mechanism. Using the example of a pipe-laying crane in the Matlab modeling environment, an imitational mathematical model has been developed that allows us to investigate the free sways of a separate load in the lateral direction, taking into account the additional balancing rope. The simulation model takes into account not only the angular degrees of freedom, but also the stretching of two sections of the cargo rope. The linear and angular energy dissipation coefficients of each of the two sections of the cargo rope, as well as the linear dissipation coefficient of the side balancing cable, are set depending on the length of the respective sections. The use of a simulation model made it possible to establish that as a result of the use of a side balancing cable connected to the main cargo cable, the attenuation coefficient of uncontrolled cargo sways in the lateral direction increases significantly. In this case, the average sway period decreases, and the logarithmic decrement of sways also increases. The dimensions of the area of sway of the cargo with this method of clearing, are reduced, which contributes to improving the safety of the workflow.

Keywords

• crane-pipelayer
• balancing rope
• sways damping
• attenuation coefficient