parametric surface modelling for rapid shell mesh setup of railway vehicle car-bodies
TRANSCRIPT
siemens.com/answers © Siemens AG 2013 – All rights reserved.
Parametric Surface Modelling for
Rapid Shell Mesh Setup of
Railway Vehicle Car-bodies
Altair Technology Conference 2013, Turin, Italy
DI T. Grausgruber*
C. Ecker
Dr M. Seitzberger
Siemens Rail Systems
Urban Transport Vienna
2013-04-24
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
AGENDA
What?
Introduction of railway vehicle car-bodies
Why?
Motivation and objectives
How?
„FastFE“ process description
Features of the CAD surface model
Automated FE preparation in HyperMesh
Conclusions
2013/04/24 Page 2
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
Siemens Infrastructure & Cities sector
2013/04/24 Page 3
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
WHAT?
Railway vehicles – car-bodies
Main load carrying mechanical structure = car-body (e.g. aluminium metro)
Made of thin walled extrusions and/or sheet metal FE shell meshes
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© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
WHAT?
Exemplary modifications of the car-body
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© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
WHY?
(1) Automated midsurface generation fails
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3D volumes of
alu extrusions
(length ~20m)
auto-
midsurfaces
midsurfaces for
FE analysis
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
WHY?
(2) Reduction in lead time
2013/04/22 Page 7
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
WHY?
(3) Reducing costs
2013/04/22 Page 8
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
HOW?
„FastFE “ process description
2013/04/22 Page 9
Efficient Modification of Global Parameters
• width, height, length of car-body
• distance between pivots, tapering
• side wall type (straight, contoured, ...)
• positions and dimensions of windows
• positions and dimensions of doors
• profile cross-sections, ...
Automated Setup of FE Model
• import and geometry cleanup
• create materials and physical properties
• mirror model (exploiting symmetries)
• enforce surface connectivity
• automated mesh generation
• create entity sets
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
HOW?
Key aspects of CAD midsurface implementation
Parameterized CAD surface model represents midsurface geometry
Assembly hierarchy with strict top-down reference structure
Global parameters in sketches control propagated reference entities
Local features and sketches to create geometry in subassemblies
fix and flexible zones of the design are defined foresightfully
Wide range of efficient modification possibilities
Parameter alteration (e.g. dimensions, No. doors/windows, …)
Change of design principle (e.g. sidewall type, longitudinal floor
extrusions transverse)
2013/04/24 Page 10
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
HOW?
CAD surface model: Top-down reference structure
2013/04/22 Page 11
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
HOW?
CAD surface model contains FE information
FE data via colour definition of faces and lines:
sheet thickness
material assignment
areas for creation of loads and boundary conditions
Models contain abstraction issues:
ready to mesh with shell elements
2013/04/24 Page 12
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
HOW?
Automated FE model setup in HyperMesh
HyperMesh scripting for perfoming the following tasks:
Create assembly hierarchy, materials, physical properties and entity sets
decode colour information (e.g. sheet thickness, beam diameter, …)
Exploit geometrical symmetry by mirroring a quarter or half model
create front/back and left/right load and boundary condition entities
Enforce surface connectivity
After model setup checks and occasionally minor fixes
Run automesher
Perfom model checks, ballasting and load/boundary condition matching
Export solver input deck and include loads and boundary conditions
Ready to run FE solver input deck
2013/04/24 Page 13
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
Conclusions
Soft-coupled CAD-CAE approach to generate FE shell meshes of car-bodies
Versatile CAD template midsurface models:
already contain abstraction issues
use sophisticated parameterization very fast project derivation
already contain necessary FE information on surfaces and lines
Efficient automated setup of high quality FE shell meshes in HyperMesh
Method enables a change from traditional design driven analysis to an
analyis driven design
Successfully applied in the concept stages of several Siemens railway
projects
2013/04/24 Page 14
© Siemens AG 2013 – All rights reserved.
Infrastructure & Cities Sector, Rail Systems Grausgruber et al. ATC 2013, Turin
Questions?
2013/04/24 Page 15
Thank you for
your attention!