Arc far Side Impact Collaborative Research Program – Task 5b: Test Procedures Crash Tests and Sled Tests for the Far-side Environment

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ARC Far Side Impact Collaborative Research Program –

Task 5b: Test Procedures

Crash Tests and Sled Tests for the Far-side Environment

Kennerly Digges

Editor

Pradeep Mohan

Chapter 1

Brian Alanso

Chapters 2, 3, 4 and 5

Joseph Cuadradro

Chapter 6

George Washington University

JUNE 2009

RAFT REPORT –

Table of Contents

1. Crash Test Configurations for the Far-side Environment 1

1.1 Introduction: 1

1.2 FEM Model Simulations: 1

1.3 IIHS Crash Test Deformations vs. Model Results 6

1.4 Discussion 8

1.5 Conclusions 8

1.6 References 8

2 Human Facet Model Validation and Dummy Evaluation 9

2.1 Introduction 9

2.2 Results 10

2.3 Conclusions 14

2.4 References 14

3 Effect of Center Console Height on Dummy Kinematics 15

3.1 Introduction 15

3.2 Methods 15

3.3 Results 16

3.4 Conclusions 20

3.5 References 20

4 Suitability of Square Acceleration Profile for Far-Side Impact Testing 21

4.1 Introduction 21

4.2 Results 21

4.3 Discussion 24

4.4 Conclusions 24

4.5 References 24

5 Far-Side Impact Vehicle Simulations with MADYMO 25

5.1 Introduction 25

5.2 Methodology 25

5.2.1 Vehicle Interiors 26

5.2.2 Dummies and Initial Setup 26

5.2.3 Crash Pulses 29

5.2.4 Reverse Seatbelts 29

5.2.5 Airbags 30

5.2.6 Test Matrix Summary 30

5.3 Results 30

5.3.1 Evaluation of Countermeasures by Each Dummy Model 30

5.3.2 Human Finite Element Model 32

5.3.3 Human Faceted Model 32

5.4 Discussion 34

5.5 Conclusions 35

5.6 References 35

6 Sled Test Configurations for the Far-Side Crash Environment 37

6.1 Introduction 37

6.2 Background 37

6.3 Methodology 38

6.4 Vehicle Model Development 39

6.5 Simulations 40

6.5.1 NHTSA 4660 30° Corner Impact Simulation 41

6.5.2 Y Damage Crash Simulations 43

6.5.3 SNCAP Crash Simulations 47

6.6 Simulation Results 51

6.7 Conclusions 52

6.8 References 53

7 Findings of Studies to Determine Crash and Sled Test Conditions 54

7.1 Summary of Study Objectives 54

7.2 Results 55

7.3 References 56

1. Crash Test Configurations for the Far-side Environment

1.1Introduction:

In Task 1, the crash environment associated with injury producing far-side crashes was defined using US Accident data and confirmed from Australian data. The analysis indicated that for belted occupants with MAIS 3+ injuries, the 50% median crash severity was a lateral delta-V of 28 kph and an extent of damage of 3.6 as measured by the CDC scale [SAE Standard J224, Collision Deformation Classification]. The most frequent damage area for seriously injured belted occupants was the front 2/3 of the vehicle (42%), followed by the rear 2/3 (21%). The most frequent principal direction of force (PDOF) was 60^o (60%), followed by 90^o (24%). The head and chest were the most frequently injured body regions, each at about 40% [Gabler 2008]. The injuring contacts that most frequently caused chest injury were the struck-side interior (23.6%), the belt or buckle (21.4%) and the seat back (20.9%) [Fildes 2007].

This task applied finite element models of vehicles and barriers to determine the degree to which the NHTSA and IIHS barriers produced the extent of damage that would be expected in a far-side crash that is representative of the 50 percentile injury producing crash. The baseline test for this study was the impact of a full size pickup truck into the side of a Taurus. For a delta-V of 28 kph and a 90 degree impact with the occupant compartment, the extent of damage was approximately 3.6.
This test formed the basis for comparing the deformation produced by the NHTSA and IIHS barriers. Other crash conditions were conducted to determine the crash severity that produced deformation that was similar in extent to the 90 degree test.

1.2FEM Model Simulations:

FE Model of the Ford Taurus was chosen as a representative mid-size sedan for this study. The model is one of the most detailed models developed at the National Crash Analysis Center. The model consists of 850K elements (Guerra, 2006). The FE model is used in this study as a target vehicle and the crush measures are taken at 4 different levels based on the US-LNCAP test protocol. The FE model of the Ford Taurus is shown in figure 1.

Figure 1: FE Model of the Ford Taurus
The US-LNCAP and the IIHS side impact barriers were used as the bullet vehicles in this study. Both of these barriers were recently developed at the National Crash Analysis Center (Kildare 2005). The barriers have been validated for the available load cell wall tests. The FE model of the US-LNCAP barrier along with the validation result is shown in figure 2. The load cell wall force from the FE model correlates well with the test data. The FE model of the IIHS side impact barrier along with the validation result is shown in figure 3. The load cell wall force from the FE model correlates well with the test data for the first 30 ms. Beyond 30 ms, the honeycomb compacts completely resulting in higher force level in the FE model. The actual crush of the barrier in the available tests into mid-size car shows that the barrier does not go into full compaction and the working limit would be within the crush observed in the first 30 ms of the load cell wall test.

The third bullet vehicle used was a GM C-1500 pick up truck.

Figure 2: FE Model of the US-LNCAP Barrier and the Load Cell Wall Force Comparison

Figure 3: FE Model of the IIHS Side Impact Barrier and the Load Cell Wall Force Comparison

The five different impact configurations and the measured lateral delta-V for each of the configuration are shown in Figure 4. The first two configurations were based on the US-LNCAP and IIHS test protocols respectively. The remaining three impact configuration was with a GM C-1500 pickup truck. In the first case the impact point was at the mid of the front door and the impact angle was 60⁰. The next case was set-up similar to the IIHS side impact protocol except that the bullet vehicle was a pick-up truck instead of the barrier. In the third case the impact point was at the front body hinge pillar.

Figure 4: Impact Configurations – NHTSA barrier; IIHS barrier, Pickup at 60^o; Pickup at 90^o; Pickup in Y-Damage configuration
The crush measures from the above impact configurations are shown in figures 5 through 7. The third impact configuration with the pick-up truck produces the max exterior crush at the windowsill. The extent of damage was about CDC 3.8. Except for the last impact configuration the other 4 cases produces similar crush characteristics. Based on these crush measures the pick-up truck impacting the mid of the front door produces the max exterior crush. The crush measures from the US-LNCAP simulation were compared to the test data available from NHTSA. The FE model yields a softer response compared to the test data. The model needs to be further validated and the front seat models needs to be included to obtain better correlation with the test data. Once the model is validated then the crush measures can be used as an input to MADYMO simulation to study the dummy kinematics with the intruding structure.



Figure 5: Max Crush at Windowsill

Figure 6: Max Crush at Mid-door

Figure 7: Max Crush at Rocker