The engineering challenges according to the pedestrian safety requirements have an important impact on the vehicle development time line and on vehicle design. The different pedestrian safety regulations that a vehicle has to fulfill (legal (ECE, GTR…) or consumer (EuroNCAP)) represent a high number of impact points that have to be defined depending on the regulation protocol. For each impact point, a FEM simulation has to be performed in order to evaluate the overall pedestrian protection performances. The integration of this process into an innovative virtual prototyping method needs a CAE tool allowing the automatic definition of the impact points and the automatic generation of ready-to-run FE models for impact simulation. Moreover, pedestrian requirements have a direct influence on vehicle design. That’s the reason why, an automatic definition of the impact points based on CAD design surfaces is a key to allow engineering judgment and design changes in the early phase of the vehicle development. The new HyperWorks Pedestrian Impact Tool, developed by Altair Engineering in cooperation with the Ford of Europe Pedestrian Protection Team, offers a perfect solution to these challenges. During the presentation, an overview of the tool capabilities will be given as well as results of an application on a Ford vehicle model.
Speakers
Dany Tapigue, Engineer, Ford Werke GmbH
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01.10.2015Ford Werke GmbH
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Content
• Background
- Assessment complexity
• Objectives
- Automatic mark up - CAD or FE data based – of test zones & grid points
- Output for CAE calculations
• Solution approach
- Altair HyperWorks pedestrian tool
• Example application
- Euro NCAP v8 protocol “Mark up on New Ford Focus”
3. 3
01.10.2015Ford Werke GmbH
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Background
• Pedestrian testing Complex full front end vehicle mark up
• Protocol and/or market dependent :
- Regulation, e.g.
ECE No. 127
GTR No. 9
...
- Consumer, e.g.
Euro NCAP (v6... v8)
...
Assessment complexity due to different protocols & markets !
4. 4
01.10.2015Ford Werke GmbH
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Objectives
Automatic mark up - CAD or FE data based – of test zones & grid points: why?
• Mark up complexity
• Various mark up per market and protocols (e.g. EU : legislation + Euro NCAP)
• Huge amount of grid points (>150) with new Euro NCAP protocol
Manual creation of test zones & grid points + impactor positioning =>
time consuming
• Accuracy & repeatability of manually generated test zones dependent on
user experience
- Deep protocol knowledge required to avoid mistakes
• Usability of scan data at early vehicle development
- GOM scan (point cloud) or rough scan surfaces difficult to assess manually
point cloud
5. 5
01.10.2015Ford Werke GmbH
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Objectives
Output
• CAD : Full vehicle front end mark up “lines and grid points”
- Based on protocols w/ manually adjustable parameters (e.g. inboard
offset of SRL, …)
• CAE : Ready to run models
- Vehicle model incl. boundary
- Impactor positioned at grid location (incl. angel & velocity)
- Contact interfaces (impactor ↔ vehicle)
• Impactor grid & transformation parameters
- For all grid points (csv-file and transform cards)
6. 6
01.10.2015Ford Werke GmbH
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Solution approach / HyperMesh pedestrian tool
• In development by Altair as cooperation work with Ford Europe pedestrian
protection team
• Completely integrated in HyperMesh, pre-processor of the HyperWorks
software suite
Process Manager to guide
the user step by step
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01.10.2015Ford Werke GmbH
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• All types of CAD files format supported (IGES; JT; STEP…)
• Final vehicle files or design surfaces supported
• RADIOSS and LS-Dyna FE models
Import vehicle
• Definition of vehicle position
• Definition of ground level
• Measurement of distances from ground and global origin
Vehicle positioning
• Import of FE impactor model
• Head; Lower-Leg; Upper-LegImport Impactor
• Regulation
• Euro NCAP V6.1, V7.0, V8.0; GTR; EU 78/2009
• Automatic markup with respect of chosen protocol
Vehicle Marking
• Selection of impact points and automatic impactor positioning
• Export of impactor transformation cards
• Export of lines and impact points as CAD file (JT format)
Position Impactor
• Automatic definition of FE contacts between Impactor and vehicle for the
selected solverDefine Contact
• Automatic export of ready to run FE models with include file structure,
for the selected impact pointsExport
Solution approach / HyperMesh pedestrian tool
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01.10.2015Ford Werke GmbH
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Example application / On New Ford Focus
Application on surface data
• Step 1: Import vehicle surfaces
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01.10.2015Ford Werke GmbH
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Example application / On New Ford Focus
• Step 2: Trim the model and keep vehicle front (only for FE model)
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01.10.2015Ford Werke GmbH
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Example application / On New Ford Focus
• Step 3: Definition of ground level (ride height)
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01.10.2015Ford Werke GmbH
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Example application / On New Ford Focus
• Step 4: Import impactor model (example with head)
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01.10.2015Ford Werke GmbH
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Example application / On New Ford Focus
• Step 5: Markup process according to the selected protocol
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01.10.2015Ford Werke GmbH
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Example application / On New Ford Focus
• Step 6: Create & export of grids and lines as CAD data
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01.10.2015Ford Werke GmbH
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Example application / On New Ford Focus
Tool output
• CAD:
- Mark up lines
- Grid points (Head, UpperLeg & FlexPLI)
• csv-file: w/ all Grid parameters
- Grid name, x-y-z coordinates, Energy & velocity (Upper Leg)
- Impactor transformation coordinates from the global origin
• Impactor transformation card: for each grid point
• FE: ready to run models w/
- Impactor (Head / UpperLeg / FlexPLI)
- Vehicle model
- Interfaces
- Vehicle boundaries
15. 15
01.10.2015Ford Werke GmbH
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• Tool try out on more/other vehicles
• Tool update
- SRL offset (along the surface for “Legislation” & Y-direction for “NCAP´s”
- UpperLeg IBRL (internal bumper reference line)
- csv-file (insert of all impact parameter)
- BRRL definition
- Intersection between bonnet rear and side reference lines
- Automatic split of child & adult grid
- Recovery file
- Implementation of corner gauge (for “Regulation” bumper test area)
- …
Next steps