Pre-requisite for efficient vehicle programs is the CAE driven development process. The accuracy of the models increases over time and leads to an increasing amount of available Concept models in databases. Due to the increased acceleration of the development process, these models are critical in providing direction on vehicle architecture in the early stages of a program. Due to the high importance of these decisions it is mandatory to trust the results of this early CAE models. Correlation of this Concept models to test or reference mainstream CAE models creates the confidence in this approach. The correlation focuses on two aspects: 1. the level of detail required to capture the detailed folding characteristic of the structure (e.g. siderail or B-Pillar) and 2. the process chain used to process the raw output from SFE Concept into RADIOSS Include files (e.g. gap, contacts, spot-welding, adhesives, bolts). This process chain is implemented using HyperMesh in batch mode, details may be found in [4]. This process chain is tuned to latest program modeling approaches and to meet the desired correlation status. In this presentation RADIOSS safety concept models are correlated to different impact modes. Tools and methods are explained focusing on both the automated evaluation of simulation output and the judgment of the correlation quality.

1. Correlation of Simulation Models
using Concept Modeling
Dr. Jörgen Hilmann, Joe Abramczyk Ford Motor Company
Dr. Salvatore Scalera RLE International
Andreas Arlt SFE GmbH Berlin

2. Correlation of Simulation Models using Concept Modeling
Dr. Jörgen Hilmann, Joe Abramczyk, Ford Motor Company
Dr. Salvatore Scalera, RLE International; Andreas Arlt, SFE GmbH Berlin
Keywords: RADIOSS, HyperMesh, MotionView, SFE Concept, Correlation, Front Impact, Side Impact
ABSTRACT
Pre-requisite for efficient vehicle programs is the CAE driven development process as described in [1], [2] "Up Front CAE". Both CAD and CAE models
based on special Concept Software as SFE CONCEPT are used to analyze the attribute performance as safety, NVH or durability and commodity studies
concerning the weight, manufacturing, or package. A database of concept models is used to minimize the modeling effort and to maximize the re-usability of
components [3]. The accuracy of the models increases over time and leads to an increasing amount of available Concept models in databases. Due to the
increased acceleration of the development process, these models are critical in providing direction on vehicle architecture in the early stages of a program.
Due to the high importance of these decisions it is mandatory to trust the results of this early CAE models. Correlation of this Concept models to test or
reference mainstream CAE models creates the confidence in this approach. The correlation focuses on two aspects: 1. the level of detail required to capture
the detailed folding characteristic of the structure (e.g. siderail or B-Pillar) and 2. the process chain used to process the raw output from SFE Concept into
RADIOSS Include files (e.g. gap, contacts, spot-welding, adhesives, bolts). This process chain is implemented using HyperMesh in batch mode, details may
be found in [4]. This process chain is tuned to latest program modeling approaches and to meet the desired correlation status.
In this presentation RADIOSS safety concept models are correlated to different impact modes. Tools and methods are explained focusing on both the
automated evaluation of simulation output and the judgment of the correlation quality. The main criteria defining the correlation fitness are video overlay of
vehicle and dummies kinematics, curve comparison of vehicles acceleration, velocity, and intrusion. Furthermore the dummy sensors have been evaluated.
The combination of the above mentioned steps enable an accelerated and more confident concept phase allowing for more alternatives being analyzed in a
more holistic and detailed manner as described in [5], [3]. This is a pre-requisite for the creation of efficient designs under the constraints of an increasingly
accelerated development process.
BIBLIOGRAPHY
[1] E. Schelkle and H. Elsenhans,
"Virtual Vehicle Development in the Concept Stage – Current Status of CAE and Outlook on the Future", 3rd MSC Worldwide Aerospace
Conference & Technology Showcase in Toulouse 2001
[2] Jörgen Hilmann (Ford) und Uwe Wagner (Ford),
„CAE driven development process for the early vehicle development phase.“ IABC Confernce 2007 in Berlin
[3] Michael Keimes, Dr. Jörgen Hilmann, Martin Lichter, Dr. Uwe Wagner,
"Optimierungsstrategien für Leichtbauprojekte" VDI Leichtbaukonfernz Ludwigsburg, 2011.
[4] Jörgen Hilmann (Ford) und Hans Zimmer (SFE GmbH)
„Development and application of an automated model built process chain for the Preprogram and Concept phase using SFE CONCEPT and the Altair
Hyperworks package.“ EHTC Konferenz in Strassbourg 2008
[5] K.H. Volz and H.Zimmer,
"Optimizing Topology and Shape for Crashworthiness in Vehicle Product Development", IABC Confernce 2007 in Berlin
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

3. Correlation of Simulation Models using Concept Modeling
Contents
• Introduction
• Motivation for Concept Modeling
• Concept Models & Libraries
• Model built and Include Files
• Correlation quality: Procedure and Criteria
• Vehicle Samples
• Q&A
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

4. Introduction
Basic Design … is a Mini Product Development Department
Project Lead Project Lead Project Lead Project Lead
B-Car C-Car CD-Car Commercial
Body Exterior
Body
Body Interior &
Attributes
Electrical
Total Basic Design Team
Electrical with Matrix Organization
Chassis - Technical Specialists
Chassis & Veh.Dyn. - Supervisors
- Base heads
Veh. Dyn.
SQ & V (NVH) - Contractors
… Concepts
Vehicle Integration
Powertrain Integration
Link
to “LHS“
Mechanical Package
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

5. Separate CAE Attribute Workstreams – OLD State
Update Effort for each attribute & Risk for misaligned program assumptions
Model Quality
Dev. Time
Safety
Pre Upda Update Update 3 Update n
decessor te1 2
NVH
Pre-decessor Update Update Update
b c x
Durability
Pre-
Update Update
dece
I II
ssor
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

6. Concept Modeling in CAE driven development process
Usage of Concept Module Libraries & Standardized Pre-Processing Procedure & Include Assembly Process
Concept module library
• Concept libraries are populated during
the concept modeling work
• Re-use of concept modules increases over time
driven through best practice initiatives
e.g. for joint execution or Pillar designs
• A process chain is implemented using
Altair Hypermesh processing re-occurring
pre-processing tasks in automated batch mode Process Chain
meshing, using
HyperWorks package
• The full vehicle models are assembled from different in batch mode
sources using the RADIOSS Include files:
- Correlated CAE models / modules from the
RADIOSS
mainstream development teams Include
- Parts / Modules developed in the concept modeling Assembly
department using e.g. SFE Concept Process
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

7. Integrated CAE Attribute Workstreams – Current State
Update Effort shared among the team & No risk for misaligned program assumptions
Model Quality
Dev. Time
Baseline study Concept development Virtual design verification
Component studies & Iterations
Pre New model model update model update
decessor VCS 1 Level VCS 2 level VCS 3 Level
Safety NVH Safety NVH Durability
Safety NVH Durability
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

8. Price of the new process: Demand for Correlation
Starting the work from correlated reference models does not require up front preparation
• In order to built CAE concept model Concept module
confidence it is mandatory to verify the
predictive power of CAE Concept models
using correlation studies.
• Herein the full vehicle models (including the
concept modules) reflect the <Job #1>
design intent of the pre-decessor model.
• The Correlation-Phase is used to familiarize Modules from the reference model
the team with the new program and to
ensure the processes used are capable. Correlated reference CAE Model
• Two Objectives for Correlation: Substitution of concept modules
1. Geometry and Mesh level of detail
2. Process to built the full vehicle model Correlation of the new model
Analysis of concept alternatives
using the same processes
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

9. Correlation types
Starting the work from correlated reference models does not require up front preparation
Difficult to standardize the correlation approach,
due to differentiation through:
• Application to geometry or the model built process chain; or both.
• Applied Car Line: B-CAR / C-CAR / CD-CAR / Light Commercial Vehicles
• Availability of reference data: Mainstream CAE and/or real test results
• Different Impact Modes: Front, Side, Rear, …
• Different Requirements / Markets
As a consequence the correlation task is challenging and
the required timing difficult to predict.
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

10. Required accuracy of the model
The Level of detail is a function of the impact mode and
FORD FOCUS
SFE Concept Geometry
SFE Concept FE Mesh
Within Ford concept models
using the same numerical code,
e.g. RADIOSS for Safety analysis.
Mainstream CAE
The level of detail ranges between both:
- A rough box section to represent an inertia effect of structure, which
is not considered to deform
- A detailed geometry with all holes and depressions if considered
being important e.g. under axial compression in a frontal impact.
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

11. Correlation Sample: Frontal Offset
Key take aways of this presentation
ODB – EuroNCAP Frontal Offset / IIHS
Model correlation status is satisfactory for:
• Siderail behavior
• Overall intrusion values
(although slight under-prediction of Toeboard intrusion)
• Crash pulse
This CAE model is w.r.t. the offset impact
well suited to support A to B comparisons
of architecture studies
Displacement delta values
ridedown area
Upper_Cowl
Offset
Dashboard
CC_Beam
ToeBoard
A_Point
Conventional
Deformable
Cowl
CAE model
Barrier
64kph
Concept
Reference model -- -- -- -- -- -- -- model
Concept model
-14mm -1mm 2mm 3mm -6mm 2mm -3mm
delta to reference
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

12. Correlation Sample: Full Frontal Rigid Barrier
Key take aways of this presentation
Straight Front – US-NCAP, SDG
Model correlation status is overall satisfactory
but there is a minor difference in the siderail bending.
As a consequence the pulse shape show
a slight deviation.
For A to B Comparisons may be used.
ridedown area
Upper_Cowl
Conventional
Dashboard
CC_Beam
ToeBoard
Full Frontal
A_Point
CAE model
Cowl
Rigid Barrier
56kph Concept
model
Reference model -- -- -- -- -- -- --
Concept model -12mm -15mm 2mm 9mm -3mm 2mm -5mm
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

13. Correlation Sample: Ford Mondeo Frontal Offset
Concept Upper Structure combined with mainstream residual modules
Dual Color Overlay: A to B comparison
Blue: Mondeo reference CAE model
Gold: Mondeo SFE CONCEPT Model
(with carry over parts e.g. Platform, PT,…)
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

14. Correlation Sample: Ford Mondeo Side Impact
Concept Upper Structure combined with mainstream residual modules
Blue: Mondeo reference CAE model
Gold: Mondeo SFE CONCEPT Model
(with carry over parts e.g. Platform, PT,…)
B-Pillar velocities B-Pillar velocities
@ @ B-Pillar-Mid
Striker
Door @ Pelvis @ Thorax
velocities
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

15. Correlation Method: Film / CAE Overlay
Overlay of a physical Test Film with a RADIOSS Crash Simulation: High Speed barrier side impact
0 ms
50 ms
AVI
100 ms
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

16. Correlation Method: Curve comparison using channels
Overlay of a physical curve measurements with RADIOSS time history readings
Accelerometer readings
Black: CAE model Black: CAE model B-pillar @
Gray: Test curves beltline
Gray: Test curves
Blue channel borders Blue channel borders A
B-pillar @
striker B
C
A B B-
pillar
@
rocker
Method:
Black: CAE model
Gray: Test curves - Create the average curve of all test curves
Blue channel borders
- Add ±15% of the average peak of the curves to define a channel
Observation:
• The accelerations evaluated using CAE model are almost always
contained in the band fluctuation of real acceleration
• The peak of the B-pillar_@_rocker acceleration is slightly
C underestimated
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

17. Correlation Method: Peak curve comparison
Overlay of a physical curve measurements with RADIOSS time history readings
Normalization: The bar charts represent the max. injury criteria
divided by the arithmetic mean of available test max. injury criteria.
“1” being the average of the available test curve maxima for this criteria, e.g. HIC36
Test Variation: The CAE results (orange bar) are in the range of test values,
except the Pubic Load for the 1st row and Spine Acceleration in the 2nd row.
1,45 1,55
1,40
1,35
1st row 1,50
1,45
2nd row
1,30 1,40
1,25 1,35
1,30
1,20
1,25
1,15
1,20
1,10
1,15
1,05
1,10
1,00 1,05
0,95 1,00
0,90 0,95
0,85 0,90
0,80 0,85
0,75 0,80
0,75
0,70
0,70
0,65
0,65
0,60
0,60
0,55
0,55
0,50 0,50
0,45 0,45
0,40 0,40
0,35 0,35
0,30 0,30
0,25 0,25
0,20 0,20
0,15
0,15
0,10
0,10
0,05
0,05
0,00
0,00 Ave5RibDis [mm] Iliac Fy
HIC36 MaxThoRib Abdomen Force Spine lowe Pelvis acceleration Pubic Fy HIC36 T12 acceleration [g´s]
acceleration Shoulder deflection [mm] T1 acceleration [g´s] Pelvis acceleration [g´s] Acetabulum Fy
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

18. Conclusions
Key take aways of this presentation
• Concept modeling significantly changed the vehicle development
towards a CAE driven Development Process,
however requires to built confidence in the used simulation models.
Demand for correlation!
• Methods are presented using visual and statistical methods to determine
the correlation quality
• These methods are objective and measurable; they help to be as
accurate as necessary to reflect the system behavior without capturing all
details of one single test result,
prevents the risk of overfitting / overpredicting to one test.
• Having solutions for concept modeling, process chain and correlation
under control you can use this approach as a generic approach for
structure development.
• Very helpful is the coupling with Topology Optimization e.g. Optistruct.
and the consideration of system noises Robustness.
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera, Andreas Arlt

19. Selecting the best Subsystems
A holistic Approach of Evolution & Revolution
SWOT Architecture Study Topology Opt.
Demands / Wishes Altair Optistruct
• System xyz is not weight
efficient enough
• Demand to improve vehicle
performance abc Competitor Evolution “white Paper”
• Part t.b.d. is not package Reference Predecessor Part D Other Part F
model Part B Segment
efficient enough
Part A Part C Part E
•… Beam representation of
the major Load Pathes
incl. Sensitivities
Concept development considering all available findings
Materialgaugeoptimization and
Materialgrade optimization
?
Safety NVH Weight
ODB/FF Static / Dyn.
2011 European HyperWorks Technology Conference
Jörgen Hilmann, Joe Abramczyk, Salvatore Scalera Andreas Arlt

20. Thanks for your attention!
Correlation of Simulation Models using
Concept Modeling
Team of Authors:
Dr. Jörgen Hilmann, Joe Abramczyk Ford Motor Company
Dr. Salvatore Scalera RLE International
Andreas Arlt SFE GmbH Berlin