Finite Element Analysis of a Newly Designed Straight Three-Layered Seale Wire Strand

A new geometry design method of three-layered Seale wire strand is proposed. The included angle between adjacent helical wires in the same layer, which is assumed as zero in the conventional design method, can be predefined arbitrarily by using the new method. The key process of deriving the diameter ratio of each layer wires was formulated into a one-dimensional problem and golden section method was applied to solve the problem efficiently. Finite element analysis of the newly developed three-layered Seale strand was also implemented by using a concise finite element model (FEM) which takes full advantage of the helical symmetry and cyclic symmetry of the three-layered Seale strand analysed in this paper. Three-dimensional solid brick elements were used for structural discretization. Nonlinear factors such as inter-wire contact and material plasticity were also taken into account. Numerical results show that the circumferential angle of helical wires is very small for the three-layered Seale strand subjected to axial tensile loads. For the 19-wire Seale strand loaded in the linear region, when included angle is predefined beyond 0.0042 degrees, it can be ensured that the helical wires in the same layer will not touch each other.