Stress Response Behaviors of Steel Wires at the Anchorage Part of Bridge Cables under Tension and Bending Coupling Loads

Abstract

The stress response behaviors of steel wires at the anchorage part of bridge cables under tension and bending coupling loads play a predominant role in determining their fatigue life and failure modes. The inherent complexity of the spiral geometry and the large diameter of actual bridge cables made the stress response behaviors of steel wires at the anchorage part unclear up to now. An analytical method was proposed for spiral steel wires at the anchorage part of semiparallel steel wire cables under tension and bending coupling loads. The corresponding refined numerical modeling method was also developed for studying the local anchorage part. Both the analytical formulation and numerical model agree well with the related experimental results in the literature. The presented analytical and numerical methods are thereby efficient and accurate to simulate bridge cables under tension and bending coupling loads. The critical slip curvature of steel wires increases linearly with the tensile strain of the bridge cable. The axial stresses of the steel wires of the bridge cable at a given longitudinal location display a linear relation with the angular change at the anchorage end. For steel wires located at the guide deviator part of the bridge cable, the axial stress behavior differs between the stick and slip states. It changes to a chord curve in the longitudinal direction in the stick state, while it follows an exponential function with respect to the polar angle in the slip state. The axial stress range of the outermost steel wire of the bridge cable increases linearly with the harmonic tension load range and the bending load range, separately. Regarding the phase difference between harmonic tension and bending coupling loads, a phase difference of 0 represents the most unfavorable combination for the bridge cable. By contrast, when the phase difference falls between 0 and π/2, the two harmonic loads tend to mutually inhibit each other’s effects on the cable’s behavior.