Session Details
MS05-2: Computational Contact Mechanics (Ganzes Minisymposium anzeigen)
Thursday, 12. October 2017; 16:00 - 18:00 Uhr in Raum 7.04
Sitzungsleitung: Christian Hesch
16:00
Adaptive finite elements for contact problems based on efficient and reliable residual-type a posteriori estimators
Mirjam Walloth (Technical University of Darmstadt)
Kurzfassung:
The talk deals with the adaptive numerical simulation of contact problems based on residual-type a posteriori estimators. The estimators are easy to compute and provably reliable, efficient and localized. The latter properties enable a good resolution of the free boundary while avoiding over-refinement in the active set of contact. We consider continuous as well as discontinuous finite elements for the numerical simulation of static and time-dependent contact problems.
Adaptive finite elements for contact problems based on efficient and reliable residual-type a posteriori estimators
Mirjam Walloth (Technical University of Darmstadt)
Kurzfassung:
The talk deals with the adaptive numerical simulation of contact problems based on residual-type a posteriori estimators. The estimators are easy to compute and provably reliable, efficient and localized. The latter properties enable a good resolution of the free boundary while avoiding over-refinement in the active set of contact. We consider continuous as well as discontinuous finite elements for the numerical simulation of static and time-dependent contact problems.
16:20
A posteriori error estimates for finite elements of higher-order for frictional, elasto-plastic two-body contact problem
Andreas Rademacher (TU Dortmund University), Hannah Frohne (TU Dortmund University)
Kurzfassung:
We present a residual a posteriori error estimator for frictional, elasto-plastic two-body contact problems and finite elements of higher order. It is based on a mixed formulation in which the constraints concerning contact, friction and plasticity are captured by Lagrange multipliers. To be able to apply a semi-smooth Newton method we solve a primal-mixed problem and calculate the plastic quantities in a post process. Reliability and suboptimal efficiency of the estimator are shown.
A posteriori error estimates for finite elements of higher-order for frictional, elasto-plastic two-body contact problem
Andreas Rademacher (TU Dortmund University), Hannah Frohne (TU Dortmund University)
Kurzfassung:
We present a residual a posteriori error estimator for frictional, elasto-plastic two-body contact problems and finite elements of higher order. It is based on a mixed formulation in which the constraints concerning contact, friction and plasticity are captured by Lagrange multipliers. To be able to apply a semi-smooth Newton method we solve a primal-mixed problem and calculate the plastic quantities in a post process. Reliability and suboptimal efficiency of the estimator are shown.
16:40
Time-adaptive non-linear finite-element analysis of contact problems
Matthias Grafenhorst (Clausthal University of Technology), Stefan Hartmann (Clausthal University of Technology)
Kurzfassung:
In recent years, mortar finite element methods have been successfully applied as space discretization scheme to a wide range of contact problems. The finite deformation contact formulation taken up is based on a mortar approach using dual Lagrange multipliers. If the constitutive models are of rate-type, the entire system of equations represents a non-smooth DAE-system. This system will be investigated in connection with higher-order time integration methods using DIRK-methods.
Time-adaptive non-linear finite-element analysis of contact problems
Matthias Grafenhorst (Clausthal University of Technology), Stefan Hartmann (Clausthal University of Technology)
Kurzfassung:
In recent years, mortar finite element methods have been successfully applied as space discretization scheme to a wide range of contact problems. The finite deformation contact formulation taken up is based on a mortar approach using dual Lagrange multipliers. If the constitutive models are of rate-type, the entire system of equations represents a non-smooth DAE-system. This system will be investigated in connection with higher-order time integration methods using DIRK-methods.
17:00
BFGS quasi-Newton finite element solver for the penalty constrained contact problems
Dusan Gabriel (Institute of Thermomechanics, Czech Academy of Sciences), Ján Kopačka (Institute of Thermomechanics, Czech Academy of Sciences), Petr Parik (Institute of Thermomechanics, Czech Academy of Sciences), Jan Masak (Institute of Thermomechanics, Czech Academy of Sciences), Jiří Plešek (Institute of Thermomechanics, Czech Academy of Sciences)
Kurzfassung:
A solution scheme for the penalty constrained contact problems is presented. The algorithm employes popular quasi-Newton solver for FE applications-the BFGS (Broyden-Fletcher-Goldfarb-Shanno) method with contact constraints enforced by the penalty method. The effectiveness of proposed solution strategy is tested by means of benchmark examples including bending dominated problems. Finally, the capability of contact solver is demonstrated in creep analysis of high pressure steam turbine casing.
BFGS quasi-Newton finite element solver for the penalty constrained contact problems
Dusan Gabriel (Institute of Thermomechanics, Czech Academy of Sciences), Ján Kopačka (Institute of Thermomechanics, Czech Academy of Sciences), Petr Parik (Institute of Thermomechanics, Czech Academy of Sciences), Jan Masak (Institute of Thermomechanics, Czech Academy of Sciences), Jiří Plešek (Institute of Thermomechanics, Czech Academy of Sciences)
Kurzfassung:
A solution scheme for the penalty constrained contact problems is presented. The algorithm employes popular quasi-Newton solver for FE applications-the BFGS (Broyden-Fletcher-Goldfarb-Shanno) method with contact constraints enforced by the penalty method. The effectiveness of proposed solution strategy is tested by means of benchmark examples including bending dominated problems. Finally, the capability of contact solver is demonstrated in creep analysis of high pressure steam turbine casing.
17:20
Singular mass matrices for isogeometric finite element analysis of dynamic contact
Anton Tkachuk (University of Stuttgart), Martina Matzen (Bornscheuer Drexler Eisele GmbH), Radek Kolman (Institute of Thermomechanics, Czech Academy of Sciences), Manfred Bischoff (University of Stuttgart)
Kurzfassung:
Usage of standard mass matrices together with implicit time integration leads to temporal oscillations of contact forces and losses/gains of energy at each contact event. Redistribution of the mass from nodes that are potentially coming into contact and removing the term corresponding to contact forces from the predictor of the Newmark method alleviates both problems. In this contribution a mass redistribution for solid isogeometric FE’s is presented and results of numerical tests are discussed.
Singular mass matrices for isogeometric finite element analysis of dynamic contact
Anton Tkachuk (University of Stuttgart), Martina Matzen (Bornscheuer Drexler Eisele GmbH), Radek Kolman (Institute of Thermomechanics, Czech Academy of Sciences), Manfred Bischoff (University of Stuttgart)
Kurzfassung:
Usage of standard mass matrices together with implicit time integration leads to temporal oscillations of contact forces and losses/gains of energy at each contact event. Redistribution of the mass from nodes that are potentially coming into contact and removing the term corresponding to contact forces from the predictor of the Newmark method alleviates both problems. In this contribution a mass redistribution for solid isogeometric FE’s is presented and results of numerical tests are discussed.
17:40
A robust explicit finite element algorithm with bi-penalty stabilization for contact-impact problems
Radek Kolman (Institute of Thermomechanics, Czech Academy of Sciences), Ján Kopačka (Institute of Thermomechanics, Czech Academy of Sciences), Anton Tkachuk (University of Stuttgart), Dusan Gabriel (Institute of Thermomechanics, Czech Academy of Sciences), José González (Universidad de Sevilla), Manfred Bischoff (University of Stuttgart)
Kurzfassung:
We present an explicit time integration scheme for finite element solution of contact-impact problems with stabilization of contact forces using a bi-penalty formulation. The stability limit for an un-penalized system is preserved by a special choice of mass and stiffness penalty parameter ratio. Moreover, the time stepping process produces stable results for a large range of the stiffness penalty parameter. Behavior of the method is shown on impact problems of heterogeneous bars.
A robust explicit finite element algorithm with bi-penalty stabilization for contact-impact problems
Radek Kolman (Institute of Thermomechanics, Czech Academy of Sciences), Ján Kopačka (Institute of Thermomechanics, Czech Academy of Sciences), Anton Tkachuk (University of Stuttgart), Dusan Gabriel (Institute of Thermomechanics, Czech Academy of Sciences), José González (Universidad de Sevilla), Manfred Bischoff (University of Stuttgart)
Kurzfassung:
We present an explicit time integration scheme for finite element solution of contact-impact problems with stabilization of contact forces using a bi-penalty formulation. The stability limit for an un-penalized system is preserved by a special choice of mass and stiffness penalty parameter ratio. Moreover, the time stepping process produces stable results for a large range of the stiffness penalty parameter. Behavior of the method is shown on impact problems of heterogeneous bars.