Tese: A three-dimensional pipe beam finite element for nonlinear analysis of multilayered risers and pipelines
Aluno(a) : Ludimar Lima de AguiarOrientador(a): Arthur Braga
Área de Concentração: Mecânica Aplicada
Data: 25/11/2013
Link para tese/dissertação: https://www.maxwell.vrac.puc-rio.br/colecao.php?strSecao=resultado&nrSeq=37192@2
Resumo: This work addresses the behavior of three-dimensional multilayered pipe beams with interlayer slip condition, under general three-dimensional large displacements, in global riser and pipeline analysis. A new finite element model, considering the Timoshenko beam for each element layer, has been formulated and implemented. It comprises axial, bending and torsional degrees-of-freedom, all varying along the element length according to discretization using Hermitian functions: constant axial and torsional loadings, and linear bending moments. Transverse shear strains due to bending are also considered in the formulation by including two generalized constant degrees-of-freedom. To represent various friction conditions between the element layers, nonlinear contact models are considered. These conditions are accounted in the model through a proper representation of the constitutive relation for the shear stresses behavior in the binding material. Derivations of hydrostatic and hydrodynamic loadings due to internal and external fluid acting on respective element layers are presented. The drag and inertia forces due to external fluid are calculated by using the Morison equation. Mass and damping matrices, associated to each element layer, are properly derived by adding their respective contributions to the expression of the virtual work due to external loading. The FE implementation allows for the numerical representation of either bonded or unbonded multilayered risers, including small slip effects between layers. Effects of the pipe-soil interaction are also addressed in this work with two contact models considering either no or full interaction between friction forces in longitudinal and lateral directions, respectively. The element formulation and its numerical capabilities are evaluated by some numerical testing, which are compared to other numerical or analytical solutions available in the literature. These tests results show that the proposed element provides a simple yet robust and reliable tool for general multilayered piping analyses.