Experimental Study on the Cable Tension Based on Non-Contact Dynamic Deflection Equipment

Abstract

For the contact and wired measurement technology of cable tension, the factors of complicated bridge site conditions, data acquisition and transmission, wave data processing and sensor contact should be considered in practical application, which affect seriously the measure result accuracy, work efficiency and the measure feasibility. In order to improve the limitation of the existing cable tension measurement technology, the feasibility and key factors of non-contact dynamic deflection measurement technology is studied. A cable specimen with length of 12m was designed and made, and the steel strand is used in it, and the non-contact vibration testing device is used. The frequency and tension of the cable and the strain of steel strands are analyzed, and the results show that the effect of measure target position on the fundamental frequency of the cable is obviously little, and the tension of the subsequent steel strand can decrease the tension strain of the stretched steel strand, that is, the tension of the stretched steel strand is reduced. Furthermore, the maximum difference between calculated and measured tension of the cable is about 17.7% during loading stage. When the unloaded cable tension is less than 20.6%, the difference between calculated and measured tension is less than 10.0%. It can be seen that the tension and tension loss of the cable can be accurately estimated by using the non-contact dynamic deflection technology, and it can improve the work efficiency and the measure feasibility due to the less measure targets and larger data transmission distance.