Yhdistetty elementti- ja diskreettielementtimenetelmä ahtojäävallin kölin muodonmuutoksen analysoimiseen kolmessa ulottuvuudessa

Abstract

In this thesis, the applicability of the combined finite-discrete element method in calculation of ridge keel loads is studied. The aim of this thesis is to implement a combined finite-discrete element method application for studying the mechanics of ridge keels and to use example cases to demonstrate the usability of the application. In this thesis, an introduction to the discrete element method is presented. This is done in order to discuss the differences in the modelling of discontinuum with the discrete element method and the combined finite-discrete element method. In the theory part of the work, first the determination of the contact force and frictional force in the combined finite-discrete element method is presented. After this, the determination of the effect of buoyancy and fluid drag in the combined finite-discrete element method is described. In the en of the theory part, the use of the energetics of a system of discrete elements to measure the accuracy of a combined finite-discrete element method simulation is presented. The examples given in this thesis demonstrate the applicability of the combined finite-discrete element method in the study of the ridge keel loads. The example cases include discussion on the penalty function method and its effect on the ridge keel deformation studies using combined finite-discrete element method. Also in the example cases, three dimensional modelling of ridge keels is discussed