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Structural Optimization of Multibody Systems

Ghandriz, Toheed ; Führer, Claus LU and Elmqvist, Hilding (2015) ECCOMAS Thematic Conference on Multibody Dynamics 2015 p.828-838
Abstract
Flexible multibody dynamics (FMD) has found many applications in control, analysis and design of mechanical systems. FMD together with the theory of structural optimization can be used for designing multibody systems with bodies which are lighter, but stronger. Topology optimization

of static structures is an active research topic in structural mechanics. However, the extension to

the dynamic case is less investigated as one has to face serious numerical difficulties. One way of extending static structural topology optimization to topology optimization of dynamic flexible multibody system with large rotational and transitional motion is investigated in this paper.

The optimization can be performed simultaneously... (More)
Flexible multibody dynamics (FMD) has found many applications in control, analysis and design of mechanical systems. FMD together with the theory of structural optimization can be used for designing multibody systems with bodies which are lighter, but stronger. Topology optimization

of static structures is an active research topic in structural mechanics. However, the extension to

the dynamic case is less investigated as one has to face serious numerical difficulties. One way of extending static structural topology optimization to topology optimization of dynamic flexible multibody system with large rotational and transitional motion is investigated in this paper.

The optimization can be performed simultaneously on all flexible bodies. The simulation part of optimization is based on an FEM approach together with modal reduction. The resulting nonlinear differential-algebraic systems are solved with the error controlled integrator IDA (Sundials)

wrapped into Python environment by Assimulo. A modified formulation of solid isometric material with penalization (SIMP) method is suggested to avoid numerical instabilities and

convergence failures of the optimizer. Sensitivity analysis is central in structural optimization.

The sensitivities are approximated to circumvent the expensive calculations. The provided examples show that the method is indeed suitable for optimizing a wide range of multibody systems.

Standard SIMP method in structural topology optimization suggests stiffness penalization. To overcome the problem of instabilities and mesh distortion in the dynamic case we consider here additionally element mass penalization. (Less)
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author
; and
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
transient response, flexible multibody dynamics, Structural topology optimization, SIMP
host publication
Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015
editor
Font-Llagunes, Josep M.
pages
11 pages
publisher
CIMNE
conference name
ECCOMAS Thematic Conference on Multibody Dynamics 2015
conference dates
2015-06-29 - 2015-07-02
external identifiers
  • scopus:84949625949
ISBN
978-84-944244-0-3
language
English
LU publication?
yes
additional info
The Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015 may be found at: http://www.multibody2015.org/frontal/img/Ebook_Multibody_2015.pdf The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Numerical Analysis (011015004)
id
d53b3b2d-cba3-4068-a5ce-d574f305fe26 (old id 7456260)
date added to LUP
2016-04-04 11:29:02
date last changed
2022-04-24 00:40:51
@inproceedings{d53b3b2d-cba3-4068-a5ce-d574f305fe26,
  abstract     = {{Flexible multibody dynamics (FMD) has found many applications in control, analysis and design of mechanical systems. FMD together with the theory of structural optimization can be used for designing multibody systems with bodies which are lighter, but stronger. Topology optimization<br/><br>
of static structures is an active research topic in structural mechanics. However, the extension to<br/><br>
the dynamic case is less investigated as one has to face serious numerical difficulties. One way of extending static structural topology optimization to topology optimization of dynamic flexible multibody system with large rotational and transitional motion is investigated in this paper.<br/><br>
The optimization can be performed simultaneously on all flexible bodies. The simulation part of optimization is based on an FEM approach together with modal reduction. The resulting nonlinear differential-algebraic systems are solved with the error controlled integrator IDA (Sundials)<br/><br>
wrapped into Python environment by Assimulo. A modified formulation of solid isometric material with penalization (SIMP) method is suggested to avoid numerical instabilities and<br/><br>
convergence failures of the optimizer. Sensitivity analysis is central in structural optimization.<br/><br>
The sensitivities are approximated to circumvent the expensive calculations. The provided examples show that the method is indeed suitable for optimizing a wide range of multibody systems.<br/><br>
Standard SIMP method in structural topology optimization suggests stiffness penalization. To overcome the problem of instabilities and mesh distortion in the dynamic case we consider here additionally element mass penalization.}},
  author       = {{Ghandriz, Toheed and Führer, Claus and Elmqvist, Hilding}},
  booktitle    = {{Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015}},
  editor       = {{Font-Llagunes, Josep M.}},
  isbn         = {{978-84-944244-0-3}},
  keywords     = {{transient response; flexible multibody dynamics; Structural topology optimization; SIMP}},
  language     = {{eng}},
  pages        = {{828--838}},
  publisher    = {{CIMNE}},
  title        = {{Structural Optimization of Multibody Systems}},
  year         = {{2015}},
}