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Peter Betsch - One of the best experts on this subject based on the ideXlab platform.
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Structure-preserving Integrators in Nonlinear Structural Dynamics and Flexible Multibody Dynamics - Structure-preserving integrators in nonlinear structural Dynamics and flexible Multibody Dynamics
CISM International Centre for Mechanical Sciences, 2016Co-Authors: Peter BetschAbstract:The Energy-momentum method for flexible Multibody Dynamics: EM integrators for elastic cosserat points.- EM integrators for rigid body Dynamics.- EM integrators for flexible Multibody Dynamics.- Foundations of time integration methods: basics of time integration in nonlinear system Dynamics.- Time integration in industrial Multibody system simulation.- Time integration methods for differential equations on manifolds.- Generalized-alpha Lie group time integration.- Spurious oscillations in generalized-alpha time integration.- The Absolute Nodal Coordinate Formulation: Introduction to ANCF.- 2D Bernoulli-Euler (thin) ANC element.- 3D shear and cross section deformable ANC element.- 2D shear and cross section deformable fully parameterized ANCF.- 2D shear and cross section deformable gradient deficient ANCF.- Selection of boundary conditions for 2D ANC elements.- 3D shear and cross section deformable ANC elements.- Variants of the energy-momentum method: Numerical time integration in solid mechanics: the role of dissipation.- The discrete gradient.- High frequency dissipative methods for nonlinear solid Dynamics.- Energy decaying, momentum conserving methods.- The Energy-Entropy-Momentum method.- Conservative and dissipative methods in flexible Multibody Dynamics: Second order time integrators.- Conservative / dissipative time integration schemes.- Lie group formalisms.- A brief course on variational integrators
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On the consistent formulation of torques in a rotationless framework for Multibody Dynamics
Computers & Structures, 2013Co-Authors: Peter Betsch, Nicolas SängerAbstract:A rotationless formulation of flexible Multibody Dynamics in terms of natural coordinates is considered. Since natural coordinates do not comprise rotational parameters, the consistent formulation and numerical discretization of actuating torques becomes an issue. In particular, the straightforward time discretization of the forces conjugate to natural coordinates may lead to a significant violation of the balance law for angular momentum. The present work shows that the theory of Cosserat points paves the way for the consistent incorporation and discretization of actuating torques. The newly proposed method adds to the energy-momentum consistent numerical integration of flexible Multibody Dynamics.
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Rotationless formulation for large deformations in flexible Multibody Dynamics
Pamm, 2011Co-Authors: Nicolas Sänger, Peter BetschAbstract:Especially for specific applications, such as contact problems, computer methods for flexible Multibody Dynamics that are able to treat large deformation phenomena are important. Classical formalisms for Multibody Dynamics are based on rigid bodies. Their extension to flexible Multibody systems is typically restricted to linear elastic material behavior whereas large deformation phenomena are formulated in the framework of the nonlinear finite element method. In the talk we address computer methods that can handle large deformations in the context of Multibody systems. In particular, the link between nonlinear continuum mechanics and Multibody systems is facilitated by a specific formulation of rigid body Dynamics [1]. It makes possible the incorporation of state-of-the-art computer methods for large deformation problems. In the talk we focus on the treatment of large deformation contact whithin flexible Multibody Dynamics [2]. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)
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Variational Integrators and Energy-Momentum Schemes for Flexible Multibody Dynamics
Journal of Computational and Nonlinear Dynamics, 2010Co-Authors: Peter Betsch, Nicolas Sänger, Christian Hesch, Stefan UhlarAbstract:This work contains a comparison between variational integrators and energy-momentum schemes for flexible Multibody Dynamics. In this connection, a specific "rotationless " formulation of flexible Multibody Dynamics is employed. Flexible components such as continuum bodies and geometrically exact beams and shells are discretized in space by using nonlinear finite element methods. The motion of the resulting discrete systems are governed by a uniform set of differential-algebraic equations (DAEs). This makes possible the application and comparison of previously developed structure-preserving methods for the numerical integration of the DAEs. In particular, we apply a specific variational integrator and an energy-momentum scheme. The performance of both integrators is assessed in the context of three representative numerical examples.
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A rotationless formulation of Multibody Dynamics: Modeling of screw joints and incorporation of control constraints
Multibody System Dynamics, 2009Co-Authors: Stefan Uhlar, Peter BetschAbstract:In the present work, a new energy-momentum conserving time-stepping scheme for Multibody systems comprising screw joints is developed. In particular, it is shown that the underlying rotationless formulation of Multibody Dynamics along with a specific coordinate augmentation technique makes possible the energy-momentum discretization of the screw pair. In addition to that, control (or servo) constraints are treated within the rotationless framework of Multibody Dynamics. The control constraints are used to partially prescribe the motion of a Multibody system. In particular, control constraints, in conjunction with the coordinate augmentation technique, make possible to solve inverse Dynamics problems by applying the present simulation approach.
Martin Arnold - One of the best experts on this subject based on the ideXlab platform.
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From Multibody Dynamics to Multidisciplinary Applications
Computational Methods in Applied Sciences, 2007Co-Authors: Martin Arnold, Andreas HeckmannAbstract:With the increasing integration of mechanical, electrical and hydraulical components in advanced engineering systems, the integrated analysis of coupled physical phenomena and coupled technical systems gets more and more important. The methods and software tools of Multibody Dynamics are used successfully as integration platform for these multidisciplinary investigations. The present paper summarizes some multidisciplinary applications in the context of Multibody Dynamics and considers common problems and solution strategies. A novel modal multifield approach for coupled field effects like thermoelasticity is discussed in more detail.
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Efficient corrector iteration for DAE time integration in Multibody Dynamics
Computer Methods in Applied Mechanics and Engineering, 2006Co-Authors: Martin Arnold, Andreas Fuchs, Claus FührerAbstract:Efficient time integration is a key issue in computational Multibody Dynamics. Implicit time integration methods for stiff systems and constrained systems require the solution of a system of nonlinear equations in each time step. The nonlinear equations are solved iteratively by Newton type methods that are tailored to the structure of the equations of motion in Multibody Dynamics. In the present paper we discuss classical and recent methods for reducing the numerical effort in the application to Multibody systems that are modelled in joint coordinates. The methods have been implemented in an industrial Multibody system simulation package. Results of numerical tests for two benchmark problems from vehicle Dynamics are presented.
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Implicit-Explicit Time Integration in Multibody Dynamics
Volume 6: 5th International Conference on Multibody Systems Nonlinear Dynamics and Control Parts A B and C, 2005Co-Authors: Martin Arnold, Gerhard HippmannAbstract:Robust and efficient time integration methods in Multibody Dynamics are tailored to the specific structure of the equations of motion. In the present paper we discuss the combination of explicit methods for non-stiff solution components with implicit methods for stiff solution components and constraints. The methods are successfully used in the dynamical simulation of large-scale Multibody system models that display a clear partitioning into stiff and non-stiff subsystems.Copyright © 2005 by ASME
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Flexible Bodies with Thermoelastic Properties in Multibody Dynamics
2005Co-Authors: Andreas Heckmann, Martin ArnoldAbstract:In flexible Multibody Dynamics elastic deformations due to thermal expansion are generally omitted since thermal displacements are usually small compared to those caused by mechanical loads. However, if a mechanical process is associated with a substantial heat generation or load, the validity of this approach has to be reviewed. In a wide range of applications such as friction brakes, thermal buckling phenomena, machine tools with thermal loads, micro-mechanical devices with resistive heating, the heat energy flow and the thermoelastic coupling cannot be ignored. In order to cope with those applications a consistent theoretical framework is introduced by the present paper that enables a combined thermal and elastic analysis in Multibody Dynamics. The theory is based on a linear material constitution that is inserted into the weak field equations of a flexible and heat conducting body. The technical relevance of thermoelastic effects like the Gough-Joule effect, thermoelastic damping and thermally excited wave propagation is reviewed. As a consequence appropriate modelling assumptions can be deduced that enable a low-dimensional formulation of the displacement and temperature field by means of a modal multifield approach. This approach is applied to a high-performance machine tool with thermal loads caused by linear induction drives.
Andreas Heckmann - One of the best experts on this subject based on the ideXlab platform.
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From Multibody Dynamics to Multidisciplinary Applications
Computational Methods in Applied Sciences, 2007Co-Authors: Martin Arnold, Andreas HeckmannAbstract:With the increasing integration of mechanical, electrical and hydraulical components in advanced engineering systems, the integrated analysis of coupled physical phenomena and coupled technical systems gets more and more important. The methods and software tools of Multibody Dynamics are used successfully as integration platform for these multidisciplinary investigations. The present paper summarizes some multidisciplinary applications in the context of Multibody Dynamics and considers common problems and solution strategies. A novel modal multifield approach for coupled field effects like thermoelasticity is discussed in more detail.
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Flexible Bodies with Thermoelastic Properties in Multibody Dynamics
2005Co-Authors: Andreas Heckmann, Martin ArnoldAbstract:In flexible Multibody Dynamics elastic deformations due to thermal expansion are generally omitted since thermal displacements are usually small compared to those caused by mechanical loads. However, if a mechanical process is associated with a substantial heat generation or load, the validity of this approach has to be reviewed. In a wide range of applications such as friction brakes, thermal buckling phenomena, machine tools with thermal loads, micro-mechanical devices with resistive heating, the heat energy flow and the thermoelastic coupling cannot be ignored. In order to cope with those applications a consistent theoretical framework is introduced by the present paper that enables a combined thermal and elastic analysis in Multibody Dynamics. The theory is based on a linear material constitution that is inserted into the weak field equations of a flexible and heat conducting body. The technical relevance of thermoelastic effects like the Gough-Joule effect, thermoelastic damping and thermally excited wave propagation is reviewed. As a consequence appropriate modelling assumptions can be deduced that enable a low-dimensional formulation of the displacement and temperature field by means of a modal multifield approach. This approach is applied to a high-performance machine tool with thermal loads caused by linear induction drives.
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Representation and Simulation of Smart Structures in Multibody Dynamics
Pamm, 2003Co-Authors: Andreas HeckmannAbstract:This paper presents a methodology for the simulation of smart structures with piezoceramic patches by means of Multibody Dynamics. Therefore, the theoretical background is outlined adapting a modal multifield approach. Then, an application example is used to illustrate the implemented process chain. This procedure provides the framework for the development of an environment in order to design, optimise and verify all vibration control elements.
Wang Ting - One of the best experts on this subject based on the ideXlab platform.
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Constraint Models Systems for Virtual Prototype Multibody Dynamics
Computer Simulation, 2006Co-Authors: Wang TingAbstract:Mechanical virtual prototype in concurrent engineering is an iterated and optimized process,in which product design and analysis are integrated.The paper proposes to extract physical properties on Multibody Dynamics from CAD when constructing mechanical virtual prototype based on component.The scheme of mapping semantic between CAD model and analysis model of Multibody Dynamics is realized based on Cartesian method of Multibody Dynamics in CAXA of 3-dimensional CAD.It analyzes how to extract coordination conversion of Multibody Dynamics constraint model in semantic of Multibody Dynamics model.It is proved that extracting physics properties on Multibody Dynamics from CAD is realizable.It can be used to construct the analysis model of Multibody Dynamics based on component and realize the development of mechanical virtual prototype.
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Research on Design Patterns Simulation Model in Virtual Prototype Multibody Dynamics
Computer Simulation, 2006Co-Authors: Wang TingAbstract:The solving model characteristic of mechanical Multibody Dynamics is analyzed in the paper,and the building of mechanical virtual prototype based on component is studied,At the same time,the building of solving simulation model of Multibody Dynamics in MVC design pattern is presented.Separating the solving logic from Multibody Dynamics model achieves the consistency of status of constraint and force element component in Multibody Dynamics system simulation.Configurations of component and simulation scheme in varies solving logics are optimized,thus making concurrent development and simulation convenient based on component.The result indicates that building mechanical virtual prototype in MVC simulation model of Multibody Dynamics based on component is feasible.
Guang Dong - One of the best experts on this subject based on the ideXlab platform.
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topology optimization for the natural frequency of Multibody Dynamics systems with multi functional components
ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, 2015Co-Authors: Guang DongAbstract:The multi-functional components layout design problem, which may have various options associated with it, including passive, active, and reactive components in given Multibody Dynamics systems, is defined in this study. The defined layout design problem is able to address the objective functions that are related to the dynamic responses of Multibody Dynamics systems, rather than static responses. The target of the multi-functional components layout design problem in given Multibody Dynamics systems is to seek the optimal interactive system layout between given multiple Multibody Dynamics system in order to maximize or minimize the dynamic objective function. The governing equations for the interactive system and the given Multibody Dynamics systems are derived first. The optimization objective is the first order natural frequency of the Multibody Dynamics system with multi-functional components in this study. The sensitivity analysis was then implemented based on the system eigen equation. Two numerical examples are presented in this study, it shows that the topology optimization method can be applied to the Multibody Dynamics system natural frequency optimization successfully.Copyright © 2015 by ASME
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Multi-Objective Topology Optimization of Multi-Functional Components in Multibody Dynamics Systems
12th AIAA Aviation Technology Integration and Operations (ATIO) Conference and 14th AIAA ISSMO Multidisciplinary Analysis and Optimization Conference, 2012Co-Authors: Guang Dong, Zheng DongAbstract:In this paper, topology optimization technique is extended to consider Multibody Dynamics systems with a much more open design space, which can include passive, active, and reactive multi-functional components. General representative models for the multifunctional components are established in a Multibody Dynamics system. The topology optimization process has been advanced for the optimization of geometrically nonlinear, time-dependent, and timing-dependent Multibody Dynamics systems undergoing large nonlinear displacements with nonlinear Dynamics responses as design objectives. The sensitivity analysis methods in this paper have made it possible to calculate the sensitivities in complicated Multibody dynamic systems and provide users with choices to signicantly reduce the computational costs, especially, in the topology optimization process, and to obtain desired accuracy in the sensitivity analysis. The single objective topology optimization problem can be redened with multiple objectives, and solved using the same sensitivity analysis methods and the multi-objective optimization algorithm, such as global criterion method.
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Time Integration Incorporated Sensitivity Analysis With Generalized-α Method for Multibody Dynamics Systems
Volume 7: Dynamic Systems and Control; Mechatronics and Intelligent Machines Parts A and B, 2011Co-Authors: Guang Dong, Gregory M. Hulbert, Noboru KikuchiAbstract:The topology optimization method is extended for the optimization of geometrically nonlinear, time-dependent Multibody Dynamics systems undergoing nonlinear responses. In particular, this paper focuses on sensitivity analysis methods for topology optimization of general Multibody Dynamics systems, which include large displacements and rotations and dynamic loading. The generalized-α method is employed to solve the Multibody Dynamics system equations of motion. The developed time integration incorporated sensitivity analysis method is based on a linear approximation of two consecutive time steps, such that the generalized-α method is only applied once in the time integration of the equations of motion. This approach significantly reduces the computational costs associated with sensitivity analysis. To show the effectiveness of the developed procedures, topology optimization of a ground structure embedded in a planar Multibody Dynamics system under dynamic loading is presented.© 2011 ASME
