Experimental determination of frequencies and tension for elastic cables

The results of experiments for the natural frequencies and tension of a cable corresponding to a scale model of a guy wire for a 411 m (1,350 ft) tall radio navigation tower are compared to the theoretical predictions. For the theoretical determination of natural frequencies, alternate methods of using curvature are presented. The first 10 natural frequencies of the cable were measured at a number of different wire tension levels and were found to differ from the theoretical values by an average of only 0.7%. The experimental results for the frequencies show clear evidence of avoided crossings. The tension at the base of the cable was determined with an accuracy of 3% by comparing the measured natural frequencies with the theoretical predictions.