スチールコードの捩り剛性

抄録

The steel cord has been widely used as a reinforcing fiber of the radial tire belt structure which is a FRR composite laminate. In this study, the torsional stiffness of steel cords having single or double layers were analyzed and verified by experimental results. Two loading cases of the regular and the reverse torsions were treated separately. In the former case a contact condition among constituent filaments twisted together in a steel cord should be considered in the analysis, in contrast to the latter case. Then, we obtained explicit formulae for these two cases. They were approximated further for a small helix angle. The predicated results for a steel cord with a single layer showed excellent agreement with experimental results in both regular and reverse torsion cases. The torsional stiffness of the steel cord with double layers were obtained approximately by superimposing two stiffnesses of constituent single layers. The calculated results are also shown to coincide well with the respective experimental results.