Isogeometric analysis applied to frictionless large deformation elastoplastic contact

This paper focuses on the application of isogeometric analysis to model frictionless large deformation contact between deformable bodies and rigid surfaces that may be represented by analytical functions. The contact constraints are satisfied exactly with the augmented Lagrangian method, and treated with a mortar-based approach combined with a simplified integration method to avoid segmentation of the contact surfaces. The spatial discretization of the deformable body is performed with NURBS and C0-continuous Lagrange polynomial elements. The numerical examples demonstrate that isogeometric surface discretization delivers more accurate and robust predictions of the response compared to Lagrange discretizations

Error Estimator for Recovered Surface Forces in Incompressible Navier-Stokes Flow

In coupled simulation of fluid-structure phenomena the important unknowns for structural design are the interface forces caused by the dynamic fluid pressure acting on the structure. By means of variationally consistent post-processing we may compute interaction forces that obey the principle of virtual work. Error estimates of the recovered quantities may be provided by solving a related (dual) adjoint problem. This may be combined with adaptive h-refinement to obtain an optimal mesh for recovery of interaction forces. The increased accuracy in forces obtained by means of the developed recovery scheme compared to traditional methods is demonstrated on an incompressible steady state example with known analytical solution. NOMENCLATURE C 0 (\Omega\Gamma set of all C 0 -continuous functions on\Omega E, E h exact- and finite element strain-rate tensors H 1 (\Omega\Gamma the Hilbert space on\Omega I the second-order identity tensor in IR 2 L2 (\Omega\Gamma set of all square-..

On Adaptive Non-Linear Shell Analysis

This paper presents an investigation of automatic adaptive numerical solutions to geometrically non-linear shell-type problems involving history-dependent materials. The paper briefly reviews an adaptive non-linear solution procedure, error estimators for history-dependent materials, an h-adaptive mesh refinement strategy and aspects of the solution transfer between the successive refined meshes. Two numerical examples are presented to illustrate some practical features of the adaptive solution procedure and the efficiency of the error estimators adopted herein

Simulation of contact between subsea pipeline and trawl gear using mortar-based isogeometric analysis

This paper focuses on the application of mortar-based isogeometric analysis to predict contact between subsea pipelines and trawl gear. The contact constraints are satisfied exactly with the augmented Lagrangian method, and treated with a mortar- based approach combined with a simplified integration method to avoid segmentation of the contact surfaces. The spatial discretization of the deformable body is performed with NURBS and C0-continuous Lagrange polynomial elements. The numerical examples demonstrate that isogeometric surface discretization delivers more accurate and robust predictions of the response compared to Lagrange discretizations

Isogeometric analysis applied to frictionless large deformation elastoplastic contact

This paper focuses on the application of isogeometric analysis to model frictionless large deformation contact between deformable bodies and rigid surfaces that may be represented by analytical functions. The contact constraints are satisfied exactly with the augmented Lagrangian method, and treated with a mortar-based approach combined with a simplified integration method to avoid segmentation of the contact surfaces. The spatial discretization of the deformable body is performed with NURBS and C0-continuous Lagrange polynomial elements. The numerical examples demonstrate that isogeometric surface discretization delivers more accurate and robust predictions of the response compared to Lagrange discretizations

Fluid-Structure Interaction Simulation Of Submerged Floating Tunnels

. A two-dimensional section model of the submerged tunnel problem is analyzed with the multiphysics finite element code SPECTRUM. The model consist of a circular cylinder submerged in sea water and subjected to constant current and regular waves. The waves are modeled by prescribing the velocity profile along the inflow boundary according to linear wave theory and by using free surface boundary conditions on the water surface. Structural boundary conditions are consistent with a global model of the submerged tunnel. A detail description of the computational model and the solution strategy that is used to solve this problem is given. The global response parameters of the cylinder (force coefficients, displacements, velocities and accelerations) obtained from the FSI-simulations are compared with a global nonlinear analysis of the tunnel using simplified models for representing the environmental loads. Knut M. Okstad, Terje Haukas, Svein Remseth and Kjell M. Mathisen 1 INTRODUCTION Be..