Implementation of constitutive equations for single crystals in finite element codes

2022 ◽  
pp. 473-494
Author(s):  
Jean-Michel Scherer ◽  
Jacques Besson
Keyword(s):  
Finite Element ◽  
Single Crystals ◽  
Constitutive Equations

Prediction of Tread Pattern Wear by an Explicit Finite Element Model3

2007 ◽  
Vol 35 (4) ◽  
pp. 276-299 ◽  
Author(s):  
J. C. Cho ◽  
B. C. Jung
Keyword(s):  
Finite Element ◽  
Wear Rate ◽  
Tangential Stress ◽  
Rate Equation ◽  
Constitutive Equations ◽  
Slip Velocity ◽  
Test Results ◽  
Explicit Finite Element ◽  
Driving Condition ◽  
Driving Conditions

Abstract Tread pattern wear is predicted by using an explicit finite element model (FEM) and compared with the indoor drum test results under a set of actual driving conditions. One pattern is used to determine the wear rate equation, which is composed of slip velocity and tangential stress under a single driving condition. Two other patterns with the same size (225/45ZR17) and profile are used to be simulated and compared with the indoor wear test results under the actual driving conditions. As a study on the rubber wear rate equation, trial wear rates are assumed by several constitutive equations and each trial wear rate is integrated along time to yield the total accumulated wear under a selected single cornering condition. The trial constitutive equations are defined by independently varying each exponent of slip velocity and tangential stress. The integrated results are compared with the indoor test results, and the best matching constitutive equation for wear is selected for the following wear simulation of two other patterns under actual driving conditions. Tens of thousands of driving conditions of a tire are categorized into a small number of simplified conditions by a suggested simplification procedure which considers the driving condition frequency and weighting function. Both of these simplified conditions and the original actual conditions are tested on the indoor drum test machines. The two results can be regarded to be in good agreement if the deviation that exists in the data is mainly due to the difference in the test velocity. Therefore, the simplification procedure is justified. By applying the selected wear rate equation and the simplified driving conditions to the explicit FEM simulation, the simulated wear results for the two patterns show good match with the actual indoor wear results.

Finite Element Simulation of the Creep Behavior of 2.25Cr-1Mo-0.25V Steel Based on Continuum Damage Mechanics

2015 ◽  
Vol 750 ◽  
pp. 266-271 ◽  
Author(s):  
Yu Zhou ◽  
Xue Dong Chen ◽  
Zhi Chao Fan ◽  
Yi Chun Han
Keyword(s):  
Genetic Algorithm ◽  
Finite Element ◽  
Creep Behavior ◽  
Constitutive Equations ◽  
Damage Evolution ◽  
Damage Mechanics ◽  
Creep Damage ◽  
Continuum Damage Mechanics ◽  
Continuum Damage ◽  
Element Simulation

The creep behavior of 2.25Cr-1Mo-0.25V ferritic steel was investigated using a set of physically-based creep damage constitutive equations. The material constants were determined according to the creep experimental data, using an efficient genetic algorithm. The user-defined subroutine for creep damage evolution was developed based on the commercial finite element software ANSYS and its user programmable features (UPFs), and the numerical simulation of the stress distribution and the damage evolution of the semi V-type notched specimen during creep were studied. The results showed that the genetic algorithm is a very efficient optimization approach for the parameter identification of the creep damage constitutive equations, and finite element simulation based on continuum damage mechanics can be used to analyze and predict the creep damage evolution under multi-axial stress states.

The Flow of UCM and Oldroyd-B Fluids Past a Cylinder

2000 ◽  
Author(s):  
Manuel A. Alves ◽  
Fernando T. Pinho ◽  
Paulo J. Oliveira
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Resolution ◽  
Constitutive Equations ◽  
Numerical Procedure ◽  
Plane Flow ◽  
Dependent Variables ◽  
High Resolution Schemes ◽  
Structured Meshes ◽  
Volume Method

Abstract Accurate solutions are obtained with the numerical method of Oliveira et al (1998) for the inertialess plane flow around a confined cylinder. This numerical procedure is based on the finite-volume method in non-orthogonal block-structured meshes with a collocated arrangement of the dependent variables, and makes use of a special interpolation practice to avoid stress-velocity decoupling. Two high-resolution schemes are implemented to represent the convective terms in the constitutive equations for the upper converted Maxwell and Oldroyd-B fluids, and the resulting predictions of the drag coefficient on the cylinder are shown to be as accurate as existing finite-element method predictions based on the very accurate h-p refinement technique.

Microcompression Behaviors of Single Crystals Simulated by Crystal Plasticity Finite Element Method

2015 ◽  
Vol 46 (11) ◽  
pp. 4834-4840 ◽  
Author(s):  
Jae-Ho Jung ◽  
Young-Sang Na ◽  
Kyung-Mox Cho ◽  
Dennis M. Dimiduk ◽  
Yoon Suk Choi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Single Crystals ◽  
Crystal Plasticity ◽  
Crystal Plasticity Finite Element ◽  
Element Method

Investigations of PMN-PT Single Crystal Performance

2010 ◽  
Author(s):  
Virginia G. DeGiorgi ◽  
E. P. Gorzkowski ◽  
M.-J. Pan ◽  
M. A. Qidwai ◽  
Stephanie A. Wimmer
Keyword(s):  
Finite Element ◽  
Electric Field ◽  
Single Crystals ◽  
Domain Switching ◽  
Fatigue Behavior ◽  
Constitutive Models ◽  
Nonlinear Behavior ◽  
Computational Effort ◽  
Basic Material ◽  
Poling Direction

Application of new materials, such as PMN-PT single crystals, requires a good understanding of basic material performance under both electrical and mechanical loading. Over the past 5 years the authors have used both computational and experimental techniques to examine the relationships between poling direction, crystal orientation, and electric field actuation. Experiments show mixed results indicating that the relationship between material orientation and loading is more complex than originally imagined. In some cases crack initiation and propagation perpendicular to the applied field was observed within a few thousand cycles but in other cases no failure was observed even after a few hundred thousand cycles despite crack growth in the presence of introduced defects. Computational effort quickly identified a gap between development of theoretical constitutive models that addressed domain switching based nonlinear behavior and what was available in workable form as part of commercial finite element codes. This led to the implementation of a macro-mechanical constitutive model which addresses domain switching, into a commercially available finite element code. The rate independent version has been used to investigate issues of electric field actuation and poling direction. Presented here are insights into the fracture and fatigue behavior of piezoelectric single crystals from both experimental and computational studies.

scholarly journals Simulation of Sheet Metal Forming Processes Using a Fully Rheological-Damage Constitutive Model Coupling and a Specific 3D Remeshing Method

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 991 ◽  
Author(s):  
Abel Cherouat ◽  
Houman Borouchaki ◽  
Zhang Jie
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Constitutive Equations ◽  
Metal Forming ◽  
Damage Mechanics ◽  
Three Dimensions ◽  
Automatic Process ◽  
Adaptive Remeshing ◽  
Fully Coupled

Automatic process modeling has become an effective tool in reducing the lead-time and the cost for designing forming processes. The numerical modeling process is performed on a fully coupled damage constitutive equations and the advanced 3D adaptive remeshing procedure. Based on continuum damage mechanics, an isotropic damage model coupled with the Johnson–Cook flow law is proposed to satisfy the thermodynamic and damage requirements in metals. The Lemaitre damage potential was chosen to control the damage evolution process and the effective configuration. These fully coupled constitutive equations have been implemented into a Dynamic Explicit finite element code Abaqus using user subroutine. On the other hand, an adaptive remeshing scheme in three dimensions is established to constantly update the deformed mesh to enable tracking of the large plastic deformations. The quantitative effects of coupled ductile damage and adaptive remeshing on the sheet metal forming are studied, and qualitative comparison with some available experimental data are given. As illustrated in the presented examples this overall strategy ensures a robust and efficient remeshing scheme for finite element simulation of sheet metal‐forming processes.

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