Determination of a Real Strain-stress State of the Steel-wire Rope Elements

摘要

Today steel-wire ropes are used as a pre-stressed reinforcement for the large-span reinforced concrete structures that are considered as solid isotropic bars. Meanwhile, it's not taken into account that the rope represents a composite structure with the axial spiral anisotropy of properties, where a combined strain-stress state (SSS) occurs. On the basis of Kirchhoff differential equations for thin curved bars, the author develops a generic mathematical model of the steel twisted rope with a linear contact of wires. This model enables one to determine a combined strain-stress state of the rope elements taking into consideration its geometrical characteristics (wire size, twist angle of a twisted rope) and mechanical characteristics of steel (elasticity and shear moduli). The paper presents calculation of irregularity of stress distribution between a core and wires of the steel rope K-7 (1+6) in case of different rates of wire twisting. Knowing the real strain-stress, state in the steel rope elements, one can specify an effective pre-stressing of the rope.