Abstract

This article describes the further development of the author's method of ice loads dynamic calculation, outlined earlier in the articles (Bolshev and Frolov, 2019, 2020). Ice loads are calculated using mathematical simulations of the dynamics of ice and structures in time domain. Special model tasks of ice destruction are considered. The mechanisms of ice failure, which may include bending and rubbling, are analyzed in the process of modelling. The article considers the conditions when different modes of failure become predominant and provides simulation examples illustrating interaction of level ice with a conical barrier. For some of the considered structures and ice fields boundary values of parameters are found at which the prevailing failure mechanism changes.

This article also presents a comparison of ice loads on inclined profile structures obtained in various experimental studies and the author's calculation method. A good agreement between the experimental and calculated data is shown.

Introduction

The study of the dynamic interaction of ice fields and marine structures by finite element methods is now generally accepted. For this modeling, both DEM and FEM methods are used. Example of DEM is presented Lau (2001) and FEM - Gürtner and Gudmestad (2008).

The choice of the element model in terms of its elastic-plastic properties causes great difficulties in known FEM programs. Ehlers and Kujala (2013) show the optimization process of these parameters for matching with experimental data. FEM methods also often use special interface elements that allow the simulation of failures and cracks in the ice field (Herrnring, Kellner, Kubiczek, Ehlers, 2019). DEM methods have problems with assigning parameters of initial elastic bonds between elements, which depend on the configuration and shape of the elements and may vary in some range (Ji, Di, Long, 2017).

The assignment of parameters for different types of critical stresses of elements in these methods is an important task. When modeling the interaction of level ice with an inclined or conical barrier, the main determining parameters of ice are usually flexural and compressive strength. However, in some failure modes the shear modulus is of primary importance. It is shown that depending on the ice parameters and the shape and size of the structure, one of the failure types may prevail, and this is not always the failure due to bend. The modeling technique proposed by the authors allows us to study various ice failure modes and their combinations in a somewhat simplified formulation, as well as to adjust the corresponding parameters of the elements to the maximum compliance with experimental and full-scale data.

This content is only available via PDF.
You can access this article if you purchase or spend a download.