Tension Measurement for Wire Ropes Based on Magneto-Elastic Effect

The bridge plays an indispensable role in people's life. To ensure the bridge safety, it is significantly crucial to detect whether the tension added on the bridge wire ropes goes beyond the limitation. There are many traditional methods to detect the tension, but those methods have some disadvantages. To improve the accuracy of tension measurement of bridge wire ropes, reduce cost and acquire convenient installation and removal process, this paper proposes a research on a magnetic flux sensor based on magneto-elastic effect and its application in measuring the tension of bridge wire ropes. A device which composed by a magnetic flux sensor and other signal processing circuits is designed and it can be used to measure the tension on the wire ropes precisely and enduringly by testing the magnetic flux through the sensor without causing damage on wire ropes. We propose a new indicator, maximal voltage, to replace the conventional integral of voltage, because the error in maximal voltage is much smaller than the integral of voltage. At the end of this paper, we validate our method by comparing two indicators for real tension and measured tension separately. The experimental results show that the maximal voltage indicator has higher linearity and can improve the accuracy of the tension measurement of bridge wire ropes.