Strength and stiffness of a reinforced flexible hose

Flexible hoses, consisting of a rubber tube reinforced by one or more cylindrical braids composed of thin steel wires, are frequently used in hydraulics. They need to be both capable of withstanding high pressures, and rather flexible, two more or less contradictory requirements. In this paper we consider a straight tube with only one steel braid. We calculate stresses and strains resulting from an internal pressure using three models of a tube. Two of these are membrane models, one with elastic steel fibres and the other with inextensible wires. The third one is a thick-walled tube model. In particular, we pay attention to the effect of the so-called neutral angle of the wires. Part of the analysis is non-linear. However, the ultimate numerical evaluation pertains to a linearized theory, i.e. the deformations are small.