Multibody Modeling of Wire Rope Reeving Systems With the ALE-ANCF Method

This paper presents an efficient finite element method for the discretization of wire ropes in multibody models of reeving systems. The method is based on line-parametrized Absolute Nodal Coordinate Formulation (ANCF) finite elements defined in the framework of an Arbitrary Lagrangian–Eulerian (ALE) description. In the ALE description the finite element nodes have variable material coordinates thus allowing the finite element to change its position within the flexible body. This property is very convenient to model wire ropes rolled in sheaves that have variable-length free spans, as usually occurs in hoisting machines. Following a previous publication by the author about the general method to model reeving systems, this paper presents a new 3D ALE-ANCF finite element that is able to describe the axial-torsional coupling behaviour of wire ropes. The constitutive model of these new elements is able to reproduce accurately experimental axial-torsion tests of non-rotating wire ropes. The new finite element method is applied to the modelling of the reeving system of a large crane and to investigate the tendency of the load to rotate around a vertical axis.