Embedded beam element with interaction surface for lateral loading of piles

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Summary This paper presents a numerical formulation for a three dimensional elasto‐plastic interface, which can be coupled with an embedded beam element in order to model its non‐linear interaction with the surrounding solid medium. The formulation is herein implemented for lateral loading of piles but is able to represent soil‐pile interaction phenomena in a general manner for different types of loading conditions or ground movements. The interface is formulated in order to capture localized material plasticity in the soil surrounding the pile within the range of small to moderate lateral displacements. The interface is formulated following two different approaches: (i) in terms of beam degrees of freedoms; and (ii) considering the displacement field of the solid domain. Each of these alternatives has its own advantages and shortcomings, which are discussed in this paper. The paper presents a comparison of the results obtained by means of the present formulation and by other well‐established analysis methods and test results published in the literature. Copyright © 2016 John Wiley & Sons, Ltd.

Section: Overview Of Embedded Beam Element Formulation With Interactimentioning

confidence: 99%

Section: Overview Of Embedded Beam Element Formulation With Interactimentioning

confidence: 99%

“…The vector field for beam displacements, u b , at the interaction surface can thus be written in terms of the beam nodal displacements,

{\overset{bold-italicu}{true}}_{bold-italicb}

, as follows:

bold u_{b} (r, φ) = {bold h}_{bold u} (r, φ) {\overset{bold-italicu}{true}}_{bold-italicb} = {bold m}_{bold u} (φ) {bold-italicn}_{bold-italicu} (r) {\overset{bold-italicu}{true}}_{bold-italicb}

The explicit form of the mapping matrix, h u , for a 2‐node (i.e., nodes i and j ) cylindrical pile in local coordinates, as shown in Figure , is given in .…”

Section: Overview Of Embedded Beam Element Formulation With Interactimentioning

confidence: 99%

“…The distributed r‐force vector field f b , at the interaction surface, can thus be written as follows:

\begin{matrix} {bold-frakturf}_{bold-frakturb} (r, φ) = {bold-frakturh}_{bold-frakturf} (r, φ) {\hat{f}}_{b} = {bold-frakturm}_{bold-frakturf} (φ) n_{f} (r) {\hat{f}}_{b} \end{matrix}

The explicit form of the mapping function h f for a cylindrical pile is given in .…”

Section: Overview Of Embedded Beam Element Formulation With Interactimentioning

confidence: 99%

Section: Validationmentioning

confidence: 99%

See 3 more Smart Citations

Three dimensional elasto‐plastic interface for embedded beam elements with interaction surface for the analysis of lateral loading of piles

Turello

Pinto

Sánchez

2016

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Analysis of lateral loading of pile groups using embedded beam elements with interaction surface

Turello

Pinto

Sánchez

2018

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Summary The numerical simulation of soil‐pile interaction problems, by means of full 3D finite element models, involves a large number of degrees of freedom (DOF) and difficulties during the mesh generation process. In order to reduce the unknowns and simplify and properly analyze such class of geotechnical problems, the so‐called embedded beam elements (EBE) have recently been developed. In a preceding contribution of the authors, an improved EBE formulation, which brings into play the soil‐pile interaction surface, was proposed with the aim to localize material plasticity in the soil surrounding the pile. This embedded beam model couples two different finite elements, each described by distinct kinematics (ie, solid and beam). The coupling is incorporated in the formulation by means of kinematical constrains established over the solid and beam displacement fields on the interaction surface. One of the main advantages of the embedded elements is that the addition of beams structural members immersed within the 3D soil model does not represent a constraint for the solid mesh, which can be adopted independently from the beam mesh. In this paper, the lateral loading of pile groups is studied by means of the proposed EBE approach with elasto‐plastic interfaces. In order to represent a rigid cap, a master node and a special set of kinematical restrictions are incorporated into the formulation. The paper presents results obtained by means of the present formulation compared against other well‐established analysis methods and test results published in the literature, for both elastic and elasto‐plastic cases.

Insight into numerical characteristics of embedded finite elements for pile‐type structures employing an enhanced formulation

Granitzer,

Tschuchnigg,

Hosseini

et al. 2023

A number of problems encountered in the field of computational geotechnics requires the modelling of numerous pile‐type structures embedded in a three‐dimensional soil continuum. Traditional modelling approaches to this problem result in computational costs that must be regarded as unbearable for most practical purposes. As an attractive alternative, we propose an enhanced embedded FE model with implicit interaction surface (EB‐I) where coupling between the contacting domains is realized by an implicit surface‐to‐volume (2D‐to‐3D) coupling scheme. As a novelty, the latter implements a non‐linear interface constitutive model that allows for explicit consideration of endpoint interaction, but does not represent a constraint for the solid mesh generation. As the slender structure is discretized employing the Timoshenko beam theory, shear deformability is explicitly considered, as opposed to earlier EB‐I‐type models reassessed in this paper. The credibility of the proposed EB‐I is numerically validated on the basis of comparative studies. It is found that the 2D‐to‐3D coupling scheme generally improves the well‐posedness of the resultant global stiffness matrix, making the proposed EB‐I computationally competitive to geometrically simplified line‐to‐volume coupling schemes. Future lines of research are carefully addressed throughout this work and include the normal stress recovery technique as well as applications to large‐scale simulations.