Application of Internal Friction Damping as a Nondestructive Evaluation Technique for Wire Rope

Abstract

This paper discusses the technical feasibility of applying internal friction damping (IFD) as a nondestructive evaluation (NDE) technique to wire rope. The paper addresses the technical feasibility, laboratory testing on wire rope, and the associated test results on various samples of wire rope. These tests were eva1 uated in a series of laboratory experiments by measurint he internal friction damping during which several test parameters were changed. The test parameters including the tensile load, frequency of test load, exposure time of rope to load and variations in rope construction are discussed from the standpoint of IFD-NDE measurements.This paper discusses the methodology for applying the IFD technique to wire rope material and construction. The experimental apparatus and specific laboratory technique are then discussed as applied to different constructions of wire rope. Next, the paper discusses the experimental results and relates them to the feasibility of employing this technique as a method of monitoring for the real world assessment of wire rope deterioration in performance. The various rope construction characteristics as tested in dry conditions are discussed. Moreover, a comparison of the affect of IFD to wire rope fatigue load conditions is presented. The paper concludes with specific conclusions and recommendations for further investigation into large diameter wire rope testing and inspection for the ultimate potential development of this technique as a real time monitoring system for marine wire rope performance.