Author(s): Oskar Veltheim; Mikko Suominen; Teemu Ikonen; Pentti Kujala

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Keywords: Sea Ice; Ships and Navigation in Ice

Abstract: To create safer and more efficient ice-going hull designs, more information about ice loads is needed. Conventional ice load measurements have focused on determining ice loads, e.g., from frames but have not took a stand on load patch. Purpose of this paper is to continue from here and to determine magnitude of loading and load patch. The hull of ropax ferry Aurora Botnia was instrumented with strain gauges during her construction. In the aft shoulder of the ship, eight strain gauges were installed on the plane field and eight shear strain gauges on the ice frames. Also, a set of physical calibration pushes were carried out after the instrumentation. The calibration pushes were done with contact areas of varying size to validate the inverse method developed to determine ice loads on the aft shoulder based on strain data. The inverse method applies an influence coefficient matrix and Tikhonov regularization. The influence coefficient matrix is based on the load-strain relation from a finite element (FE) model of the aft shoulder. An ill-posed inverse problem determining pressure on the hull is solved using Tikhonov regularization. The load patch and magnitude agreed well with the loading and load patch applied in the physical calibration pushes.

DOI:

Year: 2022