An Internal Variable Update Procedure for the Treatment of Inelastic Material Behavior within an ALE-Description of Rolling Contact

2007 ◽  
Vol 9 ◽  
pp. 157-171 ◽  
Author(s):  
M. Ziefle ◽  
U. Nackenhorst
Keyword(s):  
Contact Problems ◽  
Internal Variable ◽  
Rolling Contact ◽  
Material Behavior ◽  
Internal Variables ◽  
Arbitrary Lagrangian Eulerian ◽  
Element Analysis ◽  
Integration Schemes ◽  
Inelastic Material ◽  
Ale Methods

Arbitrary Lagrangian Eulerian (ALE) methods provide a well established basis for the numerical analysis of rolling contact problems, the theoretical framework is well developed for elastic constitutive behavior. Special measures are necessary for the treatment of history dependent and explicitly time dependent material behavior within the relative–kinematic ALE– picture. In this presentation a fractional step approach is suggested for the integration of the evolution equation for internal variables. A Time–Discontinuous Galerkin (TDG) method is introduced for the numerical solution of the related advection equations. The advantage of TDG–methods in comparison with more traditional integration schemes is studied in detail. The practicability of the approach is demonstrated by the finite element analysis of rolling tires.

A Consistent Implementation of Inelastic Material Models into Steady State Rolling

2016 ◽  
Vol 44 (3) ◽  
pp. 174-190 ◽  
Author(s):  
Mario A. Garcia ◽  
Michael Kaliske ◽  
Jin Wang ◽  
Grama Bhashyam
Keyword(s):  
Steady State ◽  
Numerical Simulations ◽  
Viscoelastic Material ◽  
Rolling Contact ◽  
Arbitrary Lagrangian Eulerian ◽  
Ale Formulation ◽  
Inelastic Material ◽  
Material Formulation ◽  
Steady State Rolling ◽  
Efficient Alternative

ABSTRACT Rolling contact is an important aspect in tire design, and reliable numerical simulations are required in order to improve the tire layout, performance, and safety. This includes the consideration of as many significant characteristics of the materials as possible. An example is found in the nonlinear and inelastic properties of the rubber compounds. For numerical simulations of tires, steady state rolling is an efficient alternative to standard transient analyses, and this work makes use of an Arbitrary Lagrangian Eulerian (ALE) formulation for the computation of the inertia contribution. Since the reference configuration is neither attached to the material nor fixed in space, handling history variables of inelastic materials becomes a complex task. A standard viscoelastic material approach is implemented. In the inelastic steady state rolling case, one location in the cross-section depends on all material locations on its circumferential ring. A consistent linearization is formulated taking into account the contribution of all finite elements connected in the hoop direction. As an outcome of this approach, the number of nonzero values in the general stiffness matrix increases, producing a more populated matrix that has to be solved. This implementation is done in the commercial finite element code ANSYS. Numerical results confirm the reliability and capabilities of the linearization for the steady state viscoelastic material formulation. A discussion on the results obtained, important remarks, and an outlook on further research conclude this work.

Finite Element Analysis of Rolling Contact Problems Using Minimum Dissipation of Energy Principle

1998 ◽  
Vol 65 (1) ◽  
pp. 271-273 ◽  
Author(s):  
S. K. Rathore ◽  
N. N. Kishore
Keyword(s):  
Finite Element ◽  
Contact Region ◽  
Contact Problems ◽  
Rolling Contact ◽  
Element Analysis ◽  
Energy Principle ◽  
Dissipation Of Energy ◽  
Rolling Surface ◽  
Strain Stress

In steady rolling motion, the loads and the fields of strain, stress, and deformations do not change with time at the contact region, as the contact region is continuously being formed by a new rolling surface. The principle of minimum dissipation of energy and the concept of traveling finite elements are made use of in solving such problems and the determination of micro-slips. The conditions of contact are discovered by use of the kinematic constraints and the Coulomb’s law of friction. A two-dimensional plane-strain finite element method along with the iterative procedure is used. The results obtained are in good agreement with expected behavior.

Nonlinear Behaviors of Submerged Floating Tunnels under Seismic Excitation

2012 ◽  
Vol 226-228 ◽  
pp. 1124-1127 ◽  
Author(s):  
Chun Xia Shi ◽  
Marco Domaneschi ◽  
Luca Martinelli
Keyword(s):  
Soil Structure ◽  
Structural Engineering ◽  
Material Behavior ◽  
Seismic Excitation ◽  
Axial Motion ◽  
Element Analysis ◽  
Inelastic Material ◽  
Multiple Support ◽  
New Type ◽  
Nonlinear Behaviors

The Submerged Floating Tunnels are one new type of infrastructure, representing a challenge in structural engineering, both on the theoretical and operational fields. In this paper, a 3D finite element analysis procedure is developed accounting for material and geometrical nonlinearities, soil-structure interaction and multiple-support seismic excitation. A comparison between dynamic response in case of elastic and inelastic material behavior of the anchor bars is given, which shows the beneficial effect of this source of energy dissipation. Furthermore, the effects of introducing dissipation devices for restraining the tunnel axial motion have been investigated as well. Besides this, the earthquake transmission through water (seaquake) is here introduced as an additional hydrodynamic loading on the tunnel. The ensuing increase of loading in the tunnel indicates that a significant role is played by this loading source and highlights the need of further investigations on seaquake effects.

Application of Adaptive Mesh and ALE Method in Simulation of Extrusion of Aluminum Alloys

2008 ◽  
Vol 367 ◽  
pp. 117-123 ◽  
Author(s):  
T. Kayser ◽  
Farhad Parvizian ◽  
C. Hortig ◽  
Bob Svendsen
Keyword(s):  
Aluminum Alloys ◽  
Adaptive Mesh Refinement ◽  
Adaptive Mesh ◽  
Contact Problems ◽  
Material Model ◽  
Extrusion Process ◽  
Material Behavior ◽  
Internal Variables ◽  
Microstructural Development ◽  
Average Grain Size

The purpose of this work is the modeling and simulation of the material behavior of aluminum alloys during extrusion processes. In particular, attention is focused here on aluminum alloys of the 6000 series (Al-Mg-Si) and 7000 series (Al-Zn-Mg). The material behavior of these alloys during extrusion is governed mainly by dynamic recovery and static recrystallization during cooling. The current material model is based on the role of energy stored in the material during deformation, as it acts as the driving force for microstructural development. The concept of internal variables is used to describe state quantities such as dislocation density, average grain size and average grain orientation. The focus of the current paper is on some of the numerical aspects of the extrusion process simulation such as contact problems and adaptive mesh refinement which should be considered in order to obtain more accurate and robust results.

Holistic Analysis of the Coupled Vehicle-Tire-Pavement System for the Design of Durable Pavements

2015 ◽  
Vol 43 (2) ◽  
pp. 86-116
Author(s):  
Michael Kaliske ◽  
Ines Wollny ◽  
Ronny Behnke ◽  
Christoph Zopf
Keyword(s):  
Coupled System ◽  
Rolling Contact ◽  
Experimental Investigations ◽  
Plastic Behavior ◽  
Arbitrary Lagrangian Eulerian ◽  
Efficient Computation ◽  
Fe Method ◽  
Ale Formulation ◽  
Inelastic Material ◽  
Holistic Analysis

ABSTRACT Pavements—an important part of worldwide infrastructure—are exposed to increasing traffic loads, new tire and vehicle concepts, and climate change. The future design of durable pavement structures requires a deep knowledge of the interactions in the coupled system of vehicle, tire, and pavement and the structural behavior of each subsystem. This paper includes recent research results in the field of tire and pavement modeling and their interaction. Furthermore, the concept for a holistic analysis of the coupled vehicle-tire-pavement system for the design of durable pavements is presented. For a realistic and numerical efficient computation of tire-pavement interaction that considers rolling contact, both subsystems are modeled using the finite element (FE) method based on an arbitrary Lagrangian Eulerian (ALE) formulation that includes inelastic material descriptions. Additionally, thermo-mechanical effects are considered for the tire computation. The base of the structural FE-ALE pavement model is the realistic numerical description of the elastic, viscous, and plastic behavior of asphalt mixes. Although initial results in the field of tire-pavement interaction were reached, much research has to be carried out to gain deeper knowledge of the coupled vehicle-tire-pavement system that includes detailed models of the subsystems and their interaction, as well as experimental investigations. The research group FOR 2089 will deal with this topic and will take the different length and timescales in particular into account.

The Role of Internal Variables on the Control of Viscoelastic Structures

2002 ◽  
Author(s):  
Luciano A. Silva ◽  
Eric M. Austin ◽  
Daniel J. Inman
Keyword(s):  
Complex Modulus ◽  
Viscoelastic Behavior ◽  
Internal Variable ◽  
Material Behavior ◽  
Internal Variables ◽  
Affect Control ◽  
Standard Observer ◽  
Full State ◽  
Internal States ◽  
Maxwell Models

Scientists have used internal variables to model time-dependent material behavior for many years. Since the 1980s they have been employed to predict transient response of structures that include viscoelastic materials. The potentially large number of extra states introduced by the internal variables can be problematic when designing control systems, so the purpose of this paper is to explore how internal variables affect control system design. Practical designs are based on output feedback of a limited number of the physical states, but this brings up the question of whether it is advantageous to recreate the full state vector (including internal states) using a standard observer. Internal variables based on Maxwell models are used to address observability and controllability as well as full- and partial-state feedback on a single-degree-of-freedom system. Comparisons are also made between complex-modulus and internal-variable representations of viscoelastic behavior.

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