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Multibody Systems (multibody + system)

Distribution by Scientific Domains

Engineering	100%

Selected Abstracts

Simulation of a deformable multibody system with hydraulics and control

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2006
Markus Dibold
Numerous contributions have been made concerning multibody systems, hydraulic actuators or the design of feedback controllers. A system that combines these fields has been studied rarely. In the present work the systematic simulation of an entire machine, which consists of structural mechanical elements where single masses are transported, hydraulic actuation systems and a closed loop controller is studied. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Efficient sampling for spatial uncertainty quantification in multibody system dynamics applications

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 5 2009
Kyle P. Schmitt
Abstract We present two methods for efficiently sampling the response (trajectory space) of multibody systems operating under spatial uncertainty, when the latter is assumed to be representable with Gaussian processes. In this case, the dynamics (time evolution) of the multibody systems depends on spatially indexed uncertain parameters that span infinite-dimensional spaces. This places a heavy computational burden on existing methodologies, an issue addressed herein with two new conditional sampling approaches. When a single instance of the uncertainty is needed in the entire domain, we use a fast Fourier transform technique. When the initial conditions are fixed and the path distribution of the dynamical system is relatively narrow, we use an incremental sampling approach that is fast and has a small memory footprint. Both methods produce the same distributions as the widely used Cholesky-based approaches. We illustrate this convergence at a smaller computational effort and memory cost for a simple non-linear vehicle model. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Numerical integration of differential-algebraic equations with mixed holonomic and control constraints

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2008
Mahmud Quasem
The present work aims at the incorporation of control (or servo) constraints into finite,dimensional mechanical systems subject to holonomic constraints. In particular, we focus on underactuated systems, defined as systems in which the number of degrees of freedom exceeds the number of inputs. The corresponding equations of motion can be written in the form of differential,algebraic equations (DAEs) with a mixed set of holonomic and control constraints. Apart from closed,loop multibody systems, the present formulation accommodates the so,called rotationless formulation of multibody dynamics. To this end, we apply a specific projection method to the DAEs in terms of redundant coordinates. A similar projection approach has been previously developed in the framework of generalized coordinates by Blajer & Ko,odziejczyk [1]. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

An effective strategy for the multibody simulation of jointed FE models in the framework of the floating frame of reference formulation.

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2008
Wolfgang Witteveen
In multibody systems (MBS), where elastic bodies are represented in the frame work of the ,floating frame of reference formulation' (FFRF), structural deformation is usually computed by the superposition of time invariant trial vectors (commonly called ,modes'). However, the mode bases, which are discussed in the literature, do not take joints into special account at the stage of mode generation. In the presented paper we propose a problem,oriented extension of classical mode bases in order to consider the presence of joints. In the novel extension which we call ,Joint Interface Modes' (JIMs), Newton's 3rd law across the joint is taken into account at the stage of mode generation, which leads to a superior convergence at the stage of mode based computation. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Modal approach for consideration of thermal states in multibody systems

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2008
Elmar Woschke
No abstract is available for this article. [source]

Validated simulation of kinematics and dynamics of multibody systems using interval and Taylor model based methods

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2007
Ekaterina Auer
In this paper, we present an integrated environment for validated modeling and simulation of kinematics and dynamics of various classes of mechanical systems SMARTMOBILE (Simulation and Modeling of dynAmics in MOBILE: Reliable and Template,based) built on top of the non-validated tool MOBILE. We outline the main features of SMARTMOBILE and its applicability area. The functionality of the new tool and the importance of the application of validated techniques are demonstrated. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Simulation of a deformable multibody system with hydraulics and control

Energy consistent time integration of planar multibody systems

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2006
Stefan Uhlar
The planar motion of rigid bodies and multibody systems can be easily described by coordinates belonging to a linear vector space. This is due to the fact that in the planar case finite rotations commute. Accordingly, using this type of generalized coordinates can be considered as canonical description of planar multibody systems. However, the extension to the three-dimensional case is not straightforward. In contrast to that, employing the elements of the direction cosine matrix as redundant coordinates makes possible a straightforward treatment of both planar and three-dimensional multibody systems. This alternative approach leads in general to differential-algebraic equations (DAEs) governing the dynamics of rigid body systems. The main purpose of the present paper is to present a comparison of the two alternative descriptions. In both cases energy-consistent time integration schemes are applied. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]