A feasibility study of tension measurement using longitudinal mode guided waves based on the magnetostrictive effect

摘要

The short cable is adopted widely in arch bridges and suspension bridges. The tension is an important parameter to guarantee the safety of the bridges in the practical application. Due to the bending stiffness and boundary condition effects, the tension of short cable is difficult to achieve accurate measurement using the flexural vibration method. A feasibility of tension measurement method for the short cable using steady state longitudinal mode guided waves based on the magnetostrictive effect is investigated. The major difference between this method and the magnetostrictive guided wave testing method is that the steady state response of the cable is employed to measure the tension. The cable is established the steady state longitudinal vibration with long time excitation based on the magnetostrictive effect. The longitudinal vibration is induced based on the inverse magnetostrictive effect. The natural frequencies of the cable are extracted from receiving data and employed to estimate the tension. The feasibility experiment results show that the natural frequencies rapidly increase with increasing the tension in low level and slightly increase with increasing the tension in high level, especially in higher modes. The results indicate that the proposed method is able to measure the tension of the short cylinder structure, but the relationship between the tension and the natural frequencies is non-linear.