A Parallel Wire Cable Tension Testing Method Based on a Permanent Magnetizer

Obtaining the cable tension accurately is important to the structural safety. Among different cable tension testing methods, the method of testing stress under the excitation of constant magnetic field is not affected by the boundary condition of the cable and avoids the affection of eddy current. Through analyzing the structural features of parallel wire cable, a cable tension testing method is presented based on the principle of testing stress under the excitation of constant magnetic field. An experiment setup is carried out to verify the feasibility of the method.

Effect of Tensile Load for Detecting Broken Wires of Parallel Wire Cable Based on Guided Waves

Condition assessment of cables has gained more attention for the bridge safety. The cable is under tensile load in service. The effect of tensile load for detecting broken wires on parallel wire cable based on guided waves is investigated. The sample cable with broken wires under several levels of tensile load is detected using guided waves based on the magnetostrictive effect. The amplitude of flaw echo increases monotonically with the increasing of tension. The results indicate that the tensile load brings benefit for detecting broken wires in the parallel wire cable.

Fatigue Properties Assessment of Corroded Cable

Based on fatigue test results of corroded wires obtained from dissection of actual parallel wire cables which were used on a certain domestic cable-stayed bridge, the fatigue properties of corroded parallel wire cable are investigated by the method of Monte Carlo simulation in this paper. The results of fatigue life and corrosion degree of corroded wire are presented. Comparisons between the original design information and fatigue test results, it can be seen that corrosions make the fatigue lives of wires decreasing sharply. The fatigue life of individual wire is described by Weibull distribution considered some useful parameters such as, stress range, mean stress, mean static strength and length effects. The effects of percentage of broken wire, cable S-N curve parameter on cable fatigue life are discussed. It can be seen that the cable fatigue lives are controlled by a small fraction of the cable wires with the shortest fatigue lives. Finally, the S-N curves of cable are calculated by Monte Carlo simulations based on the results of individual wire fatigue test, and compared with the results of cable fatigue test.