scholarly journals FINITE ELEMENT IMPLEMENTATION OF GEOMETRICALLY NONLINEAR CONTACT

2021 ◽  
Vol 30 ◽  
pp. 18-23
Author(s):  
Ondřej Faltus ◽  
Martin Horák
Keyword(s):  
Finite Element ◽  
Large Strain ◽  
Small Strain ◽  
Geometrically Nonlinear ◽  
Finite Element Software ◽  
Finite Element Implementation ◽  
Algorithmic Solution ◽  
Code Base ◽  
Nonlinear Contact ◽  
Current Code

The OOFEM finite element software has been recently updated to include contact algorithms for small strain applications. In this work, we attempt to extend the contact algorithms to large strain problems. Reviewing the current code and comparing it with approaches encountered in literature, we arrive at a specific algorithmic solution and integrate it into the current code base. The current code is explained, the necessary extensions are derived and documented, and the algorithmic changes are described. Tests confirm the functionality and quadratic rate of convergence of the proposed implementation.

Non-Conservative and Conservative Loads in Geometrically Nonlinear Shells

2003 ◽  
Author(s):  
Cho W. S. To ◽  
Meilan L. Liu
Keyword(s):  
Finite Element ◽  
Large Strain ◽  
Small Strain ◽  
Shell Structures ◽  
Element Formulation ◽  
Geometrically Nonlinear ◽  
Hybrid Strain ◽  
Shell Elements ◽  
Updated Lagrangian Formulation ◽  
Updated Lagrangian

Responses of geometrically nonlinear shell structures under combined conservative and non-conservative loads are investigated and presented in this paper. The shell structures are discretized by the finite element method and represented by the hybrid strain based three node flat triangular shell elements that were developed previously by the authors. The updated Lagrangian formulation and the incremental Hellinger-Reissner variational principle are employed. Features such as large or small strain deformation, finite rotation, updated thickness so as to account for the “thinning effect” due to large strain deformation, and inclusion or exclusion of the mid-surface director field are incorporated in the finite element formulation. Representative results of two examples are included to demonstrate the capability, accuracy and efficiency of the computational strategy proposed.

Three-Dimensional Nonlinear Contact Finite Element Analysis of Mandibular All-on-4 Design

2015 ◽  
Vol 41 (2) ◽  
pp. e12-e18 ◽  
Author(s):  
Mostafa Omran Hussein ◽  
Mahmoud Elsayed Rabie
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Equivalent Stress ◽  
Stress And Strain ◽  
Element Analysis ◽  
Implant Position ◽  
Finite Element Software ◽  
Edentulous Mandible ◽  
Nonlinear Contact ◽  
Position And Orientation

The All-on-4 design was used successfully for restoring edentulous mandible. This design avoids anatomic cripples such as inferior alveolar nerve by tilting posterior implants. Moreover, tilting posterior implants of All-on-4 design had a mechanical preference than the conventional design. On the other hand, the anterior implants are parallel at the lateral incisor region. Several researches showed favorable results for tilting posterior implants. However, research did not study the influence of the anterior implant position or orientation on the mechanical aspects of this design. This study analyzes the influence of varying anterior implant position and orientation of the All-on-4 design using nonlinear contact 3D finite-element analysis. Three copied 3-dimensional models of the All-on-4 design were classified according to anterior implant position and orientation. The frictional contact between fixtures and bone was the contact type in this finite element analysis. Finally, von Mises stress and strain at implant and bone levels were recorded and analyzed using finite element software. Stress concentrations were detected mainly around the posterior implant at the loaded side. Values of the maximum equivalent stress and strain were around tilted implants of design III followed by design II, then design I. Changing the position or orientation of the anterior implants in All-on-4 design influences stress-strain distribution of the whole design.

Two-Dimensional Geometrically Nonlinear Finite Element Formulation for Analysis of Straight Pipes

2020 ◽  
Author(s):  
Saher Attia ◽  
Magdi Mohareb ◽  
Michael Martens ◽  
Nader Yoosef Ghodsi ◽  
Yong Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Virtual Work ◽  
Strain Tensor ◽  
Structural Response ◽  
Small Strain ◽  
Nonlinear Finite Element ◽  
Finite Element Formulation ◽  
Single Element ◽  
Element Formulation ◽  
Geometrically Nonlinear

Abstract The paper presents a new and simple geometrically nonlinear finite element formulation to simulate the structural response of straight pipes under in-plane loading and/or internal pressure. The formulation employs the Green-Lagrange strain tensor to capture finite deformation-small strain effects. Additionally, the First Piola-Kirchhoff stress tensor and Saint Venant-Kirchhoff constitutive model are adopted within the principle of virtual work framework in conjunction with a total Lagrangian approach. The formulation is applied for a cantilever beam under three loading conditions. Results are in good agreement with shell models in ABAQUS. Although the solution is based on a single element, the formulation provides reasonable displacement and stress predictions.

The Research on Instant Contact Deformation of Round Link Chain Based on Symmetric Penalty Function Method

2012 ◽  
Vol 619 ◽  
pp. 361-364
Author(s):  
Wei Kang Li ◽  
Jun Mao
Keyword(s):  
Finite Element ◽  
Penalty Function ◽  
Working Condition ◽  
Penalty Function Method ◽  
Analysis Software ◽  
Element Analysis ◽  
Finite Element Software ◽  
Nonlinear Contact ◽  
Sudden Loading ◽  
Stress And Deformation

In order to analyze deformation and stress state of round link chain which it is generated by instant impact for sudden loading between the chains during the working condition, the method of symmetric penalty function was adopted to analyze contact between round link chains; and the finite element software ANSYS LS-DYNA was further used to carry on nonlinear contact analysis, the displacement curves , the stress and deformation with time were gained during the process of impact by simulating the process of the instant impact of chains. The results show that it is circular to the contact area of round link chains and it is the main reasons of damage that the greater stress and deformation of impact is caused when time lasts 0.05s through theoretical analysis and finite element analysis software. The theory equations of load conditions and the method of finite elements can provide a theoretical basis and simulation methods for analyzing the round link chain driving in a variety of different working conditions under the conditions of impact.

scholarly journals Geometrically nonlinear finite element implementation based on highly accurate 1st and 2nd numerical derivative scheme using hyper-dual numbers

2016 ◽  
Vol 82 (834) ◽  
pp. 15-00454-15-00454 ◽  
Author(s):  
Masaki FUJIKAWA ◽  
Kiyotaka ISHIKAWA ◽  
Chobin MAKABE ◽  
Masato TANAKA ◽  
Takashi SASAGAWA ◽  
...  
Keyword(s):  
Finite Element ◽  
Nonlinear Finite Element ◽  
Geometrically Nonlinear ◽  
Dual Numbers ◽  
Finite Element Implementation ◽  
Numerical Derivative

Multiscale Constitutive Model Development and Finite Element Implementation for Magnetostrictive Materials

2007 ◽  
Author(s):  
William S. Oates
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Axial Magnetic Field ◽  
Mean Field Approximation ◽  
Ferromagnetic Behavior ◽  
Length Scale ◽  
Modeling Framework ◽  
Finite Element Software ◽  
Finite Element Implementation ◽  
Magnetostrictive Materials

A multiscale constitutive model is developed and applied to magnetostrictive materials to predict multi-axial ferromagnetic switching. The modeling framework is an extension of a one-dimensional homogenized energy model that employs a stochastic distribution of localized magnetic moments. Here, the model is extended to multi-axial ferromagnetic switching in a polycrystalline ferromagnetic material. A mean-field approximation is adopted to quantify ferromagnetic switching from multi-axial magnetic field loading at the single crystal length scale. Polycrystalline ferromagnetic behavior is modeled by homogenizing stochastic distributions of underlying microscopic fields associated with material inhomogeneities at the grain length scale. Approximations of the stochastic distributions are made to improve computational efficiency for finite element implementation. The constitutive model is numerically validated and implemented in the commercial finite element software, COMSOL.

Sign in / Sign up

Export Citation Format

Share Document