A mixed 3D-1D finite element formulation for analysis of geomaterial structures with embedded curvilinear inclusions: application to load transfer in mooring anchor systems

Abstract

A finite element model for structural analysis of media with embedded inclusions is presented. The "embedded element concept" is adopted to model the contact interaction of two medium components along the contact interface considering a mixed 3D-1D formulation. The Mohr-Coulomb interface model is employed to define the bond-stress and bond-slip relation and strains associated with bond-slip are assumed to remain infinitesimal along the interface. Nonlinear analysis is performed with a corotational kinematics description introduced in the context of embedded approach. The problem of load transfer in mooring anchor systems was investigated and reasonable results were obtained using the present model.

Numerical Simulation of Load Transfer in Mooring Anchor Systems

“…Considering that all kinematics variables are known at configuration t = t n , the displacement field can be obtained from integration of the strain rate tensor in the time interval [t n ,t n+1 ]. The strain increment is computed at the reference configuration t = t n+1/2 in the corotational system by using a mid-point integration rule [6]…”

“…Meanwhile, k n and k s refer to normal and tangential stiffness moduli in force per cubic length. The aforementioned equation is obtained in [6] by applying the consistency condition and forcing a null component of displacement in the normal direction.…”

“…Variables p t and r t are respectively the nodal external forces of soil and cable, while q uu and q ww refer to corresponding internal nodal forces. The explicit expressions of these matrices can be found in reference [6] and the reader is referred to that work for details . After assembling all element contributions, the set of equations of the incremental form of the nonlinear problem of the coupled system is written in the following form:…”

“…This approach is efficient considering that size of the inclusion is much smaller than the size of the soil medium. The solid elements are represented by eight-node one point integration finite elements with stabilization matrices to avoid locking, rank deficiency and spurious modes [6]. However, they may suffer from convergence problems when plasticity problems are involved.…”

Desenvolvimento de um código computacional para o estudo analítico e numérico do fenômeno da elastoplasticidade unidimensional

“…Problemas de engenharia estrutural bem como engenharia geotécnica são modelados com a utilização de elementos unidimensionais (BRAUN, et al, 2018). O concreto armado é o exemplo mais comum, sendo as barras de aço modeladas como elementos de cabo e incorporadas a modelagem de elementos finitos referente ao concreto.…”