Novel Sensor Technology for Identifying Subsea Power Cables’ and Umbilicals’ Axial Stiffness

Abstract

This paper presents how to establish the axial stiffness for subsea power cables and umbilicals based on multiple measurement points along the test object. The Cartesian coordinates of the measuring points are measured with use of a total station consisting of an electronic theodolite integrated with an electronic distance measurement unit. The advantage of the total station compared to other displacement measuring systems is that the sensors are not in physical contact with the test object. The measurement method, including calculation of elongation and axial stiffness, is evaluated through a full-scale test with a super duplex steel tube with known mechanical properties. The deviation between the theoretical axial stiffness of the steel tube and the measurement method is 1.2%.