A Novel Integrated Sensor for Stress Measurement in Steel Strand Based on Elastomagnetic and Magnetostrictive Effect

Abstract

AbstractThe deteriorating state of steel strands can be assessed using information of its overall and local stress level. An integrated sensor, which is based on magnetostrictive and elastomagnetic effect, is proposed for stress measurement of seven-wire steel strands. This integrated sensor can alternatively measure the stress level of seven-wire steel strands through guided wave-based technique and elastomagnetic method. When it works as magnetostirctive sensor to generate longitudinal guided wave in strand, the missing frequency band occurred in received wave signal is investigated in a pre-tensioned strand. It is found that the missing band central frequency increases linearly as the value of natural logarithm of overall stress increases. The integrated sensor can be applied to measure local stress in a strand based on elastomagnetic effect. The output signal amplitude of the sensor has linear relationship with strand stress level and stress increment of less than 10 MPa can be identified. The characteristic functions for both local and overall stress measurement are pre-calibrated experimentally. The proposed integrated sensor has great potential for applications of steel strands stress measurement.KeywordsLocal StressStress MeasurementIntegrate SensorShort Time Fourier TransformTransmitter CoilThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.