Session Details
CS05: Damage and Plasticity
Friday, 13. October 2017; 08:30 - 10:30 Uhr in Raum 7.31
Sitzungsleitung: Frederik Fahrendorf
08:30
Evaluation of a Gradient Enhanced Damage Plasticity Model for Shotcrete
Matthias Neuner (University of Innsbruck), Magdalena Schreter (University of Innsbruck), Günter Hofstetter (University of Innsbruck)
Kurzfassung:
A damage plasticity model representing the time-dependent and nonlinear material behavior of shotcrete is discussed. In order to obtain mesh-insensitive numerical results upon strain softening, an over-nonlocal implicit gradient enhancement is employed. The capabilities of the model are demonstrated by means of finite element simulations, employing meshes of different size and orientations.
Evaluation of a Gradient Enhanced Damage Plasticity Model for Shotcrete
Matthias Neuner (University of Innsbruck), Magdalena Schreter (University of Innsbruck), Günter Hofstetter (University of Innsbruck)
Kurzfassung:
A damage plasticity model representing the time-dependent and nonlinear material behavior of shotcrete is discussed. In order to obtain mesh-insensitive numerical results upon strain softening, an over-nonlocal implicit gradient enhancement is employed. The capabilities of the model are demonstrated by means of finite element simulations, employing meshes of different size and orientations.
08:50
Study of the Regularization Scheme of an Advanced Rock Model
Magdalena Schreter (University of Innsbruck), Matthias Neuner (University of Innsbruck), Günter Hofstetter (University of Innsbruck)
Kurzfassung:
Quasi-brittle materials such as rock exhibit strain softening in the post-peak region leading to failure. The application of an advanced constitutive model for rock predicting irreversible deformation, strain hardening and strain softening is discussed. The aim is to the study the regularization scheme of the rock model based on the over-nonlocal implicit gradient enhancement in numerical simulations of a biaxial compression test.
Study of the Regularization Scheme of an Advanced Rock Model
Magdalena Schreter (University of Innsbruck), Matthias Neuner (University of Innsbruck), Günter Hofstetter (University of Innsbruck)
Kurzfassung:
Quasi-brittle materials such as rock exhibit strain softening in the post-peak region leading to failure. The application of an advanced constitutive model for rock predicting irreversible deformation, strain hardening and strain softening is discussed. The aim is to the study the regularization scheme of the rock model based on the over-nonlocal implicit gradient enhancement in numerical simulations of a biaxial compression test.
09:10
Variational constitutive updates based on hyper-dual numbers - theory of gradient enhanced thermoplasticity
Volker Fohrmeister (TU Dortmund University), Alexander Bartels (TU Dortmund University), Jörn Mosler (TU Dortmund University)
Kurzfassung:
We present a generic framework for thermomechanically coupled gradient-enhanced plasticity theory based on variational constitutive updates, i.e., all relevant equations are fulfilled by minimizing an incremental potential. Within the numerical implementation, the exact derivatives of this potential are computed by means of hyper-dual numbers. By doing so, the laborious task of implementation is highly reduced.
Variational constitutive updates based on hyper-dual numbers - theory of gradient enhanced thermoplasticity
Volker Fohrmeister (TU Dortmund University), Alexander Bartels (TU Dortmund University), Jörn Mosler (TU Dortmund University)
Kurzfassung:
We present a generic framework for thermomechanically coupled gradient-enhanced plasticity theory based on variational constitutive updates, i.e., all relevant equations are fulfilled by minimizing an incremental potential. Within the numerical implementation, the exact derivatives of this potential are computed by means of hyper-dual numbers. By doing so, the laborious task of implementation is highly reduced.
09:30
Regularisation of gradient-enhanced damage coupled to finite plasticity
Leon Sprave (TU Dortmund University), Andreas Menzel (TU Dortmund University)
Kurzfassung:
An isotropic gradient-enhanced damage formulation is coupled to finite von Mises plasticity. In the context of finite elements an additional field variable, representing nonlocal damage, is introduced. In a multisurface approach, the evolution of damage and plasticity are governed by their respective criteria. Simulation results are compared to experimental data to verify the model.
Regularisation of gradient-enhanced damage coupled to finite plasticity
Leon Sprave (TU Dortmund University), Andreas Menzel (TU Dortmund University)
Kurzfassung:
An isotropic gradient-enhanced damage formulation is coupled to finite von Mises plasticity. In the context of finite elements an additional field variable, representing nonlocal damage, is introduced. In a multisurface approach, the evolution of damage and plasticity are governed by their respective criteria. Simulation results are compared to experimental data to verify the model.
09:50
On the modelling of evolving material symmetries in finite strain plastic deformations
Tobias Asmanoglo (TU Dortmund University), Jia Lu (University of Iowa), Andreas Menzel (TU Dortmund University), Panayiotis Papadopoulos (University of California)
Kurzfassung:
Motivated by the experimental findings on sheet metal presented in (J. Mech. Phys. Solids 45, 22, 841--851, 1997) we focus on the elaboration of a specific model which allows us to capture the evolution of the plastic anisotropy that is induced by finite strain plastic deformations. We discuss evolution equations for the structural tensor that characterises the material symmetry group and show that the finite element based simulation results are in good agreement with experimental findings.
On the modelling of evolving material symmetries in finite strain plastic deformations
Tobias Asmanoglo (TU Dortmund University), Jia Lu (University of Iowa), Andreas Menzel (TU Dortmund University), Panayiotis Papadopoulos (University of California)
Kurzfassung:
Motivated by the experimental findings on sheet metal presented in (J. Mech. Phys. Solids 45, 22, 841--851, 1997) we focus on the elaboration of a specific model which allows us to capture the evolution of the plastic anisotropy that is induced by finite strain plastic deformations. We discuss evolution equations for the structural tensor that characterises the material symmetry group and show that the finite element based simulation results are in good agreement with experimental findings.
10:10
Eigenerosion Approach for Drucker-Prager Plasticity
Aurel Qinami (Technische Universität Dresden), Michael Kaliske (Technische Universität Dresden)
Kurzfassung:
The eigenfracture scheme is a suitable technique to model brittle fracture. This method faces challenges when dealing with inelasticity. The contribution at hand is focused on an eigenerosion formulation for Drucker-Prager plasticity. Its binary approach, leading to element stiffness degradation, can be implemented in a straightforward manner into a finite element code. Special attention is paid to the distinction of tension and compression. The method is validated by a numerical example.
Eigenerosion Approach for Drucker-Prager Plasticity
Aurel Qinami (Technische Universität Dresden), Michael Kaliske (Technische Universität Dresden)
Kurzfassung:
The eigenfracture scheme is a suitable technique to model brittle fracture. This method faces challenges when dealing with inelasticity. The contribution at hand is focused on an eigenerosion formulation for Drucker-Prager plasticity. Its binary approach, leading to element stiffness degradation, can be implemented in a straightforward manner into a finite element code. Special attention is paid to the distinction of tension and compression. The method is validated by a numerical example.