Development of continuum mechanics based beam elements for linear and nonlinear analyses of multi-layered composite beam and helically stranded cable structures

Abstract

In this thesis, novel continuum mechanics based beam finite elements for the linear and nonlinear analyses of multi-layered composite beams and multi-layered helically stranded cable structures are introduced. The primary feature of the proposed beam finite element is an advanced modeling capability that originates from the general 3D geometry and displacement interpolations of the continuum mechanics based beams. The continuum mechanics based beam formulation enables much simpler and more efficient modeling procedure using relatively small number of the degree of freedom (DOF), because the entire geometry of the layered beam is modeled as a single beam model instead of modeling the each individual sub-component of the beam. Thus, it is possible to deal with the behavior of the entire multi-layered beam and helically stranded cable structures regardless of the numbers of layers and sub-components. The modeling capability and the performance of the proposed beam element model were verified through several numerical examples. The proposed beam finite element exhibits excellent predictive and modeling capabilities to deal with complicated geometries including arbitrary numbers of layers and wires, composite cross-sections, eccentricities in addition to various loading conditions. Further, the proposed beam finite element is successfully applicable for predicting the nonlinear behaviors of the multi-layered beam and cable structures while considering the geometrical and material nonlinearities of the sub-components as well as the nonlinear load-slip relation.