Structural Optimization of Multibody Systems
Author
Editor
- Josep M. Font-Llagunes
Summary, in English
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.
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.
Department/s
- Mathematics (Faculty of Engineering)
- Numerical Analysis
Publishing year
2015
Language
English
Pages
828-838
Publication/Series
Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015
Document type
Conference paper
Publisher
CIMNE
Topic
- Mathematics
- Mechanical Engineering
Keywords
- transient response
- flexible multibody dynamics
- Structural topology optimization
- SIMP
Conference name
ECCOMAS Thematic Conference on Multibody Dynamics 2015
Conference date
2015-06-29 - 2015-07-02
Status
Published
Research group
- Numerical Analysis
ISBN/ISSN/Other
- ISBN: 978-84-944244-0-3