PSI - Issue 46

A. Wetzel et al. / Procedia Structural Integrity 46 (2023) 10–16 Anna Wetzel et al. / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 2. Scheme of the technical stranding process.

Nomenclature α

wire/rope lay angle

d ε ε t F l s n μ

diameter

strain

true strain

force

lay of length

M

torsional moment rotational speed friction coefficient tensile strength yielding limit angle of torsion v. Mises stress

R m R p

φ S σ t

true stress velocity

v

2. Material A round strand wire-rope of the type 6x7 with a wire steel core (WSC) connects the seat-belt buckle and the car body. A section view of this rope is depicted in Fig. 3.a). This rope is stranded twice. First, the wires are stranded to the central and the outer strands. Then, those seven strands are stranded into the rope. In this case, each strand consists of seven single wires. The central wire of each strand has a larger diameter than the surrounding wires. For the core strand, the diameter of the central wire d 1 is 0.52 mm and d 2 = 0.48 mm respectively for the outer wires. Fig. 3.b) depicts the true stress-strain curves of the two different wire sizes of the core strand used as input data for Abaqus. The diagram shows that the yielding limit R p is about 1300 MPa for the central wire and about 1800 MPa for the outer wires. The tensile strength R m is about 2300 MPa for the central wire and about 2500 MPa for the outer wires. The low strain at tensile strength R m indicates a brittle material behavior.