Research on Monitoring Point Layout of Health Monitoring System of the Icebreaker

Abstract

As one kind of special ship, polar Ice-breaking ships are used to break the ice for other ships or for researchers going deeper to the polar region. The safety of Ice-breaking ships should be emphasized not only because of it special shape but also because of its unique load case and complex marine environment. Structure Health Monitoring (SHM) should be installed in them owing to reasons mentioned above, even if there are rules that had been used while designing the ships. How to choose appropriate monitoring points is one of the most important things in this whole project. For providing more rational approach to selecting measure points in Structure Health Monitoring by FEM analysis, two methods were proposed and compared in order to determine a better one which can reduce the workload. One of these two methods is design wave approach which can show ultimate strength but just in the case of hogging, sagging and other typical cases, which ignore a large number of cases the ship may meet. The other one is composed of 240 structural responses from 20 kinds of frequencies in 12 directions (Data of spectral analysis), and weighted mean value based on ocean wave spectrum would be seen as an assessment of the damage caused by natural environment. For huge data in the finite element analysis, there must be a set of feasible algorithms to automatically process the results to get monitoring points. After that the monitoring point can be and stress measured by fiber-optic sensor at that point will be monitored in real time.