SAFETY ENHANCED INNOVATIONS FOR OLDER ROAD USERS. EUROPEAN COMMISSION EIGHTH FRAMEWORK PROGRAMME HORIZON 2020 GA No

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1 SAFETY ENHANCED INNOVATIONS FOR OLDER ROAD USERS EUROPEAN COMMISSION EIGHTH FRAMEWORK PROGRAMME HORIZON 2020 GA No Deliverable No. Deliverable Title Dissemination Level D3.4b Validated updates to pedestrian impactors for testing Public Written by Mark Burleigh Humanetics Checked by Oliver Zander BASt 28/02/2018 David Hynd TRL 08/03/2018 Approved by Marcus Wisch BASt 09/04/2018 Issue date 09/04/2018 This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No

2 EXECUTIVE SUMMARY This report is a document to support the FlexPLI with Upper Body Mass (UBM) demonstrator delivered in the project and to validate the design requirements in Deliverable 3.1b. For the Thorax Injury Prediction Tool (TIPT) details of the launch fixtures and jacket are shown. The results of physical tests with TIPT and FlexPLI with UBM against generic frontends and actual vehicles will be reported in Deliverable 4.2. No new test tool has been developed in pedestrian safety for many years so the initial development in SENIORS could lead to an important addition to vehicle front end safety. After analysis from simulations for the Head Neck Impactor (HNI) it was decided not to manufacture hardware as the benefit from simulation was not as positive as expected, see Deliverable 3.2b. Contributions of the partners: HIS Supplying hardware for FlexPLI leg and UBM parts and supporting TIPT testing and fixture design BASt Report review and hardware testing of FlexPLI with UBM and TIPT IDIADA Hardware testing of TIPT FCA Hardware testing FlexPLI with UBM Page 2 out of 20

3 Contents Executive summary Introduction The EU Project SENIORS Background to this Report Objectives of this Deliverable Design Validation FlexPLI with UBM Introduction Design Considerations and Implementation Design Criteria Assessment Conclusion Thorax Impactor (TIPT) Introduction Proposed TIPT Vehicle Setups, Pusher Design TIPT Jacket Design Criteria Assessment / Conclusion Conclusion Glossary References Annex 1 (CAE Results: Narrow Knee Front Lobe) Acknowledgments Disclaimer Page 3 out of 20

4 1 INTRODUCTION 1.1 THE EU PROJECT SENIORS Because society is aging demographically and older people are frailer the SENIORS (Safety ENhanced Innovations for Older Road users) project aims to improve the safe mobility of the elderly using an integrated approach that covers the main modes of transport. This project primarily investigates and assesses the injury reduction in road traffic accidents that can be achieved through suitable tools, test and assessment procedures, as well as safety systems in the area of passive vehicle safety. The goal is to reduce the numbers of fatally and seriously injured older road users for both major groups: car occupants and external road users (pedestrians, cyclists). The SENIORS project consists of four technical Work Packages (WP1 WP4) which interact and provide the knowledge needed throughout the project. These WPs are: WP1: Accidentology and behaviour of elderly in road traffic WP2: Biomechanics WP3: Test tool development WP4: Current protection and impact of new safety systems In addition, there is one Work Package assigned for the Dissemination and Exploitation (WP5) as well as one Work Package for the Project Management (WP6). The overall scope for the SENIORS project is shown in the flowchart below. Quantification of needs Literature (injury, behaviour, ) Accident studies Initial benefit assessment Achievable injury prevention Analysis of risks Derivation of safety strategies IDENTIFICATION OF NEEDS / PRIORITIES FOR OLDER ROAD USERS Prioritise Future project activities Biomechanical testing Dummies / impactors Numerical models Injury criteria IMPROVED TOOLS Injury risk curves Test procedures Assessment procedures * To be confirmed from the accident analysis CAR OCCUPANT Better older thorax IRC * Obese occupant Active HBM PEDESTRIAN/CYCLIST Flex-PLI with UBM Head-neck Pedestrian thorax Head-neck and pedestrian thorax will be early-stage research Safety of older road users Effectiveness of new tools and advantages of new procedures Applied to current and advanced new safety systems Passive Active BENEFIT AND IMPACT ASSESSMENTS Integrated benefit analysis Page 4 out of 20

5 1.2 BACKGROUND TO THIS REPORT Further to the design specifications reported in D3.1b (Burleigh M, 2016) and simulation work carried out on the lower leg impactor (FlexPLI with Upper Body Mass), Head Neck Impactor (HNI) and the Thorax Impactor Protection Tool (TIPT) as described in D3.2b, (Zander, 2018) this report supports the demonstrator tools delivered and to be tested in the project. The addition of an upper body mass attached to the FlexPLI is intended to provide more realistic kinematics and loading to the leg as it will simulate the lower torso mass of a human during a vehicle impact event. Adding to an existing tool also reduces the cost to uses for test tool hardware. There is no test tool available to evaluate thorax injury for vulnerable road user impacts to vehicle bonnets. Providing a test tool for such injury would improve frontend design and reduce injury. SENIORS aims to improve and develop test tools to represent the elderly during collision events. The injury patterns identified in WP1 are addressed by adaptations to existing pedestrian impactors by: Adding an Upper Body Mass (UBM) to the FlexPLI legform impactor; and Using a side impact crash test dummy ribcage EuroSid 2 (ES-2) (Humanetics, 2017) as a pedestrian impactor to assess injuries caused by vehicle frontends. SENIORS actions related to the development and revision of test tools were divided into the following activities: Design specifications: requirements for the test tools to be developed. Design validation: virtual test tools for pedestrians and other vulnerable road users. Tool certifications: certification requirements, procedures and results including setup/positioning information, handling and assembly. Tool Validations: realization of test tools for pedestrian safety based on the previously defined requirements. 1.3 OBJECTIVES OF THIS DELIVERABLE The objective of this document is to show that test tools supplied to the consortium for testing are validated to the design specifications in Deliverable 3.1b (Burleigh M, 2016). Page 5 out of 20

6 2 DESIGN VALIDATION FLEXPLI WITH UBM 2.1 INTRODUCTION The FlexPLI legform is used for car bumper testing. This is a standard product used in UN Regulation 127, (UNECE, 22 January 2015), Euro NCAP (NCAP E., 2017) and is expected to be incorporated in GTR9 (Global Technical Regulation) in June 2018 (UNECE, 22 January 2015). To improve its biofidelity an Upper Body Mass (UBM) has been added to the top of the leg to represent the inertial mass of the lower torso of a human being struck by a vehicle from the side. From human body modelling and simulation results the mass has shown to improve the kinematic behaviour and provide more realistic loading to assess injuries. The UBM is particularly important for the assessment of femur injuries, the baseline FlexPLI cannot assess femur injury because the lack of an upper body mass means that the femur does not interact with the vehicle front in a humanlike way. This applies to all vehicles but more so against high bumper vehicles like SUVs and crossovers. The femur of the standard FlexPLI does not bend due particularly against flat faced higher bumpers. The FlexPLI leg was chosen to add the mass as it is the current state-of-the-art leg impactor which has already been fully validated (Konosu, 2009) and is widely available in test institutions worldwide. 2.2 DESIGN CONSIDERATIONS AND IMPLEMENTATION Some durability concerns were discussed in the project regarding the additional loading that would be applied to the leg from the UBM, particularly the knee and the femur bone. Some ideas and solutions were considered like adding rotational stops in the knee or stronger wires, reducing the wire activation stops in the femur and adding bushes to the segment link pivots. Even redesigning some parts was considered to help potential durability and address issues like impacts to curved bumper surfaces and the reported high non biofidelic Anterior Cruciate Ligament (ACL) and Posterior Cruciate Ligament (PCL) ligament deflections on the bumper edges. Simulations were performed against a generic test rig (Pardede, 2015) with three corrugated steel bumpers representing the spoiler, bumper and Bonnet Leading Edge (BLE), see Annex 1. Corrugated steel was used as this could be accurately validated in Finite Element (FE) model. This simulation was done with a generic sedan, sports car and SUV. Only results on the sports car and sedan are shown in the annex. The simulation had a narrower front lobe (outer medial condyle) in the knee which was implemented to see if this could address the high ligament deflection behaviour by reducing the knee lobe width to be more in line with an actual human knee bone. It was considered that this could reduce the lateral tilt angle of the Page 6 out of 20

7 knee that was producing the higher ACL and PCL ligament elongations seen in practice. This did show a very small reduction in the ACL and PCL ligament elongation in oblique impacts for the generic sedan and sports car (2 mm) but was not significant enough to consider modifying the knee. A new design would be required but affecting the performance of the leg which was not desirable. Perpendicular impact performance was not affected. See Annex 1 for design modification considered and simulated ligament elongations. It was decided any changes would affect established biofidelity, which was not justifiable for the small benefit observed in the simulations. Therefore, alongside a further investigation of durability, in the meantime a number or spares were provided in case of part failure. Further to the suggestion in the design requirements of a mass with a flexible element, this was considered along with the rigid mass design developed in the APROSYS project. (J Bovenkerk, 2009). The rubber element would allow rotation of the mass at the hip joint location and provide a time lag of the UBM seen in the human body model simulation. See Figure 1 for an overview of the design. Both rigid and flexible UBM leg designs were simulated, see Deliverable 3.2b (Zander, 2018). Both simulations showed similar performance with slight advantages of the flexible design, so it was decided to test both designs and see which provided the best all round performance. The flexible element design copied the same weight as the rigid design as this had been proven to be satisfactory in the APROSYS project (J Bovenkerk, 2009). The mass was going to rotate forward so this governed its internal U-shape to avoid contact with the leg when rotated forward after impact. The centre of gravity (CoG) of the flexible design is lower than the rigid mass perhaps representing the lower pelvis more than the total human torso. This reduces the moment on the rubber element and should help with in-flight stability. It is also a pragmatic approach to simulating the upper body mass and the applied loading to the vehicle. The rubber element has its neutral axis (wire support) slightly forward to encourage forward rotation. The outer urethane cover represents the pelvis flesh and will help absorb any hard contact with the vehicle or test floor to prevent damage. The interface plate with the leg has a guide slot to hold the leg on the launcher. A new launcher attachment has been designed and adapted to the current launcher pusher plate (as used in the Consortium) to support the mass when accelerated from the ram. The pusher attachment must align with the CoG of the upper mass for stable flight. Page 7 out of 20

8 Figure 1 UBM with flexible element assembled to top of FlexPLI. Leg flesh not shown Table 1 shows the materials, CAD masses and actual masses. Compliance to the design target was within 25 grams. Table 1 UBM weights CAD and actual UBM Part Weights Above Flexible Element Part Material CAD Mass (kg) Actual Mass (kg) UBM Steel Cover Polyurethane Screws, nuts & Washers Steel UBM Part Weights Below & Including Flexible Element Base Aluminium Rubber Element Assembly Rubber & Stainless Steel Support Wires Assemblies x2 Stainless Steel Screws Steel Total expected Page 8 out of 20

9 To some extent the rigid UBM has already been validated in the APROSYS project in a real test environment as well as in simulation. When tested in APROSYS it showed promising results to predict realistic femur injury compared to the FlexPLI but the physical tests were limited. Figure 2 Rigid upper mass (Bovenkerk et al. 2009) It was agreed to manufacture two flexible UBM assemblies and a further rigid UBM in SENIORS as one already was manufactured during the APROSYS project. 2.3 DESIGN CRITERIA ASSESSMENT Durability: No durability problems have been reported. Biofidelity: This will depend on performance and correlation to injury and a new transfer function would be expected. This will be assessed after testing has been completed. Handling: The design of both the flexible and rigid UBM is simple and no handling problems have been reported. The standard 13.2kg FlexPLI leg does now weigh 7kg more but this is not considered a problem. Repeatability & Reproducibility: Results will be evaluated after testing has been completed. There are two legs being tested so if the same test is repeated on both legs a limited reproducibility check can be done. To ensure the rubber element produces the same performance it would be necessary to dynamically test the part to establish the same performance each time and that the performance is maintained after testing. This will probably be required after every tests and use a pendulum test set up. The whole assembly may also require a new high speed dynamic certification. Sensitivity: It should be possible to evaluate sensitivity with the different bumper profiles being tested. Sensitivity to angled corner bumpers will also be possible. Page 9 out of 20

10 Instrumentation: No additional instrumentation has been added to the UBM only the standard 12 channel FlexPLI sensors are being used. Kinematics of the leg with UBM will be assessed using high-speed video and compared to HBM simulation and the leg without the UBM to see improvements. 2.4 CONCLUSION Regarding the design and manufacture of both the flexible and rigid UBM the parts meet the design specification. This also applies to the new fixtures to launch the leg with the UBM. Full validation is not possible without testing and comparison to human body models, this will be shown in Deliverable 4.2b. Therefore only validation of the UBM design has been done here. 3 THORAX IMPACTOR (TIPT) 3.1 INTRODUCTION Each test lab will supply an ES-2 torso to test in the project. A fixture to adapt the tool to existing guide rails on each partner s launcher guides has been designed. The mass of the torso with launch adaptors will be around 22kg. Therefore the launcher will need to accelerate a mass of around 26kg as the pusher is expected to weigh around 4kg. The expected impact velocities will be between 15 and 21 km/h and pointing downward. This is the torso speed after a 40 km/h vehicle impact to the lower legs. The body rotates towards the bonnet at this lower speed. This speed has been checked with simulation and with an actual pedestrian dummy. A CAD model of the TIPT with adaptors, CoG balance weights and pusher plate is shown in figures 3 to 5. A special Neoprene jacket will cover the TIPT. The arm is to be fixed on the TIPT by sowing the sleeve onto the body of the jacket in a downward position, in line with the spine, see Figure 6. This should improve repeatability as the ES-2 dummy arm and shoulder were designed to move away from the impact when inside a vehicle to expose the ribs for injury. This mechanism could have proven to be unrepeatable due to the lighter TIPT and the way the shoulder components interact. For the TIPT impact, exposing the ribs directly to a vehicle bonnet could damage the TIPT so it was decided to keep the arm on the assembly for testing. Removing the arm could be an option for later testing but some kind of protective cover like a urethane sheet over the ribs would likely be needed to avoid damage. Page 10 out of 20

11 3.2 PROPOSED TIPT VEHICLE SETUPS, PUSHER DESIGN Three basic setups will be used for a Sedan, SUV and Van/MPV. Each vehicle required a different geometry. These geometries are from simulations and are justified in Deliverable 3.2b (Zander, 2018). Actual vehicles and a generic SAE buck (Takahashi, 2014) will be used for testing to validate the TIPT. For the Sedan the TIPT will be tilted down 75⁰ from the horizontal and the launcher guide tilted down 19⁰ from the horizontal. For the SUV the TIPT will be tilted forward 70⁰ to the horizontal and the launcher guide tilted down 23⁰ from the horizontal. For the Van/MPV the TIPT will be tilted forward on the pusher 62⁰ from the horizontal and the launcher guide angle will be tilted down 5⁰ from the horizontal. See Figure 3. It was requested to design the fixture for any expected angle so the fixture was designed with a plus and minus tolerance of 15⁰ about the mean on the pusher angles above. This meant the CoG changed with each set up and the balance weights had to be adjustable to keep it balanced when accelerated towards the vehicle. Two designs were made (one per test lab) for one see Figure 4 manufactured mainly from aluminum to keep the mass low to meet launch speed and one made from steel, see Figure 3. The pusher was made from steel for practical reasons for the mass there was not critical for the ram. Therefore the balance weights had to be different. It was also requested to launch the TIPT parallel to the bonnet surface as that is how the deflection sensors are oriented in the dummy. This setup would look at direct loading through the sensor. This will help to understand any issues with the angled impacts with regard to sensitivity with the one directional sensors in the ribs. As the first fixture design did not allow for this setup, additional bolt on parts were designed see Figure 5. Page 11 out of 20

12 Figure 3 TIPT pusher (made from steel) for 56⁰ tilt, jacket not shown Figure 4 shown TIPT pusher (made from aluminum) with adjustable mass, jacket not Page 12 out of 20

13 Figure 5 Pusher adapted for parallel launch to bonnet, jacket not shown 3.3 TIPT JACKET The jacket is based on the standard ES-2 jacket (Humanetics, 2017), the following modifications were made: 1. A longer sleeve was added for the struck side 2. Jacket cut down to just below the depth of the ribs 3. The non-struck side sleeve is removed 4. Zip shortened 5. Long sleeve is sown against the jacket body The jacket will be an important part for testing, it will help protect flesh parts and provide consistent friction for surface interaction on impact so will help repeatability. (See Figure 6). Page 13 out of 20

14 Figure 6 TIPT Jacket 3.4 DESIGN CRITERIA ASSESSMENT / CONCLUSION Durability: Yet to be established after testing. Biofidelity: The ES-2 is already established so similar injury criteria could be considered, however this will depend on performance and correlation to injury and a new transfer function would be expected. Handling: The intended handling of the TIPT should not be an issue, it is a well-known and used dummy and users will be very familiar with its design. At around 22 kg it will not be too difficult to lift and access to parts will be much easier than on the ES-2 dummy. Repeatability & Reproducibility: As with durability this will not be established until testing has been completed and analysed. As two TIPT s will be tested in two laboratories it may be possible to look at reproducibility to some extent if the same test is done in both labs. A problem was observed with the pusher fixture. The TIPT rotated after launch before impact making precise target position difficult particularly with the y axis. The weight of the TIPT also affected the impact angle. It was a challenge to design a light pusher and achieve all the adjustment angles specified. This meant the CoG of the TIPT was not the same as the ram guides once if left the fixture. Improvement to the design will be investigated to reduce this effect. This of course was a completely new untested prototype launcher and initial testing was carried out effectively, therefore the launcher design achieved its requirement. Page 14 out of 20

15 Sensitivity: This will also have to be assessed after testing particularly with the three different car types being tested. The best check could be with the generic SAE buck as repeatability would be more reliable. The different impact angles could produce different results with the linear deflection sensors in the ribcage. Having the arm fitted to the TIPT could also create sensitivity issues but as explained earlier this was considered necessary, at least initially to protect the ribs from damage. Instrumentation: The ES-2 has three linear guided deflection sensors and accelerometers can be fitted to the ribs, lower spine and shoulder to establish loading forces. Fitting angular velocity sensors could also help analyse kinematics after impact. 3.5 CONCLUSION Only the design has been validated in this report, full validation can only be completed after testing and comparison to Human body model responses, see report 4.2b. The TIPT meets the design criteria set out in the design specification. Page 15 out of 20

16 4 GLOSSARY Term APROSYS ACL BASt BLE CAD CAE CoG EuroSID FE FlexPLI HBM HNI ISO MCL PCL PMHS SENIORS TIPT TRL UBM Definition Advanced Protection Systems; Large scale EU FP5 project Anterior Cruciate Ligament; part of the structure of the knee Bundesanstalt für Straßenwesen Bonnet Leading Edge Computer Aided Design Computer Aided Engineering Center of Gravity European Side Impact Dummy Finite Element; a type of numerical modelling Flexible Pedestrian Leg form Impactor Human Body Model Head-neck impactor International Organization for Standardization Medial Collateral Ligament Posterior Cruciate Ligament; part of the structure of the knee Post Mortem Human Subject Safety ENhanced Innovations for Older Road users Thorax Injury Protection Tool Transport Research Laboratory Upper Body Mass Page 16 out of 20

17 5 REFERENCES Brüll, S., Bovenkerk, J., & Kalliske, I. (2009). New and improved test methods to address head impacts. Deliverable D3.3.3C of the FP 6 Project on Advanced Protective Systems (APROSYS). Burleigh M, L. P. (2016). Design Specifications for improved pedestrian test tools. Burleigh M, Lemmen P, Zander O. (2016). Design specifications for improved pedestrian tools (D3.1b) SENIORS Deliverable Report. Humanetics. (2017). Humanetics User manual harmonised ES-2 E H rev H. J Bovenkerk, O. Z. (2009). Evaluation of the extended scope for FlexPLI obtained by adding an upper body mass. APROSYS (D3.3.3H) AP-SP33-026R. APROSYS. Konosu. (2009). Atsuhiro Konosu and Takahiro Issiki; Yukou Takahashi and Hideki Suzuki; Bernard Been and Mark Burleigh; Takahiro Hirasawa and Hitoshi Kanoshima; Development of a Biofidelic Flexible Pedestrian Legform Impactor Type GTR Prototype. ESV NCAP, E. (2016). European New Car Assessment program 'Pedsetrian testing protocol Version 8.3' Euro NCAP December EURO NCAP. NCAP, E. (2017). European New Car Assessment Programme, Pedestrian Test Tool Protocol Version 8.4 Euro NCAP. O, Z. (2018). Updated Impactor Test and Validation Report, Ott J, Lundgren C, Fornells A, Luera A. Pardede. (2015). Development of enhancehed LS-Dyna Model with new round robin test data using regulated hardware. Pardede V, Shah C, 10th Praxis Conference. Takahashi, Y. (2014). Yukou Takahashi, Miwako Ikeda, Hiroyuki Asanuma, Christian Svensson, Bengt Pipkorn, Christian Forsberg, Rikard Fredriksson, Full-scale Validation of generic Buck for Pedestrian Impact Simulation. IRCOBI. UNECE. (22 January 2015). Regulation No series of ammendments to the Regulation. ENECE. Zander. (2018). Oliver Zander, Juliian Ott, Christer Lundgren, Alba Fornells, Andrea Luera; Updated Impactor Test and Validation Report; D3.2b. ECE SENIORS. Page 17 out of 20

18 6 ANNEX 1 (CAE RESULTS: NARROW KNEE FRONT LOBE) Page 18 out of 20

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20 ACKNOWLEDGMENTS This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No DISCLAIMER This publication has been produced by the SENIORS project, which is funded under the Horizon 2020 Programme of the European Commission. The present document is a draft and has not been approved. The content of this report does not reflect the official opinion of the European Union. Responsibility for the information and views expressed therein lies entirely with the authors. Page 20 out of 20