New safety systems have reduced the number of automotive neck injuries. However, this has benefited the male population more than the female population, with a reduction of injuries for males up to 65% greater than for females. This is possibly due to the predominant use of the average-sized male dummy in both product development and legislation testing. Several projects have been initiated to close the gap in protection between males and females. The EU project ADSEAT developed a prototype of an average-sized female dummy, the BioRID P50F. In 2017, a Finite Element (FE) human body model (HBM) representing an average female was presented, the ViVA. It was further developed, in the EU project VIRTUAL, into models of both average females and males, theVIVA+ models, which served as the basis for the design concepts of two Seat Evaluation Tools (SET 50F and SET 50M). The SETs were designed to form a bridge between physical testing and virtual testing in rear impact safetyassessment. They serve as a tool to validate vehicle seat models for virtual testing. The FE models of the SETswere developed to create a virtual representation of the hardware SETs. An important focus of the developmentof the SETs was the kinematics of the spine, as well as the body surface contour, to ensure a biofidelic interaction with vehicle seats. An additional ambition with the SETs is to provide biofidelic head relative to torso responses, addressing soft tissue neck injury protection evaluation of vehicle seats in low velocity rear impacts.  

The objective of the present study was to analyze whether the kinematics of an isolated head-neck model can replicate those observed on a whole body model in order to reduce simulation time in development or optimization tasks. Previous studies have shown how muscle controllers improved head-neck kinematics responses over a passive neck muscle implementation. These studies used volunteer T1 displacement time histories prescribed on the model T1 as the loading input to develop the neck controller characteristics. It was not clear whether the implementation of a controller based on volunteer kinematics with an isolated head-neck model was directly transferable to a full-body model. The current study shows that the head-neck model produced almost identical responses as the full body model for the first 200ms of the event for most kinematic variables. The head rotational displacement corresponded well during the first 150ms. The isolated head-neck model predicted more displacement and rotations than when mounted on a full-body model. The current simplification of a head-neck model still produced reasonable kinematic responses during the critical time period to assess soft tissue neck injuries, making it suitable for developing and tuning neck muscle controllers. 

Differences in injury risk between females and males are often reported in field data analysis. The aim of this study was to investigate the differences in kinematics and injury risk between average female and male car occupants, pedestrians and cyclists, under well-controlled boundary conditions. Therefore, a simulation study comprising the newly introduced VIVA+ human body models was performed, representing the first model line-up consisting of average female and male models originating from the same base model. A generic vehicle interior, detailed seat models and a generic vehicle exterior were used to simulate crash scenarios close to those currently tested in consumer information tests. Differences in injury risks, load distribution and injury mechanisms were observed between the average female and male VIVA+ models for different load cases and body regions. While in some load cases, loading was more severe for the average female, opposite trends have also been observed. In order to understand trends observed in the field and to derive appropriate countermeasures, further variations in load cases and anthropometries should be considered in future work using the tools presented in this study.  

Crash test dummy kinematics is commonly obtained from high-speed video recordings or other opticalmethods. The present study evaluates a cost-efficient sensor system combining gyros and accelerometers toderive the kinematics of different parts of a dummy. This evaluation was done on the newly designed humansurrogates, the Seat Evaluation Tools (SET) 50F and 50M, developed for low severity rear impacts and hereequipped with gyros at four locations

Objective: An integrated assessment framework that enables holistic safety evaluations addressing vulnerable road users (VRU) is introduced and applied in the current study. The developed method enables consideration of both active and passive safety measures and distributions of real-world crash scenario parameters.

Methods: The likelihood of a specific virtual testing scenario occurring in real life has been derived from accident databases scaled to European level. Based on pre-crash simulations, it is determined how likely it is that scenarios could be avoided by a specific Autonomous Emergency Braking (AEB) system. For the unavoidable cases, probabilities for specific collision scenarios are determined, and the injury risk for these is determined, subsequently, from in-crash simulations with the VIVA+ Human Body Models combined with the created metamodel for an average male and female model. The integrated assessment framework was applied for the holistic assessment of car-related pedestrian protection using a generic car model to assess the safety benefits of a generic AEB system combined with current passive safety structures.

Results: In total, 61,914 virtual testing scenarios have been derived from the different car-pedestrian cases based on real-world crash scenario parameters. Considering the occurrence probability of the virtual testing scenarios, by implementing an AEB, a total crash risk reduction of 81.70% was achieved based on pre-crash simulations. It was shown that 50 in-crash simulations per load case are sufficient to create a metamodel for injury prediction. For the in-crash simulations with the generic vehicle, it was also shown that the injury risk can be reduced by implementing an AEB, as compared to the baseline scenarios. Moreover, as seen in the unavoidable cases, the injury risk for the average male and female is the same for brain injuries and femoral shaft fractures. The average male has a higher risk of skull fractures and fractures of more than three ribs compared to the average female. The average female has a higher risk of proximal femoral fractures than the average male.

Conclusions: A novel methodology was developed which allows for movement away from the exclusive use of standard-load case assessments, thus helping to bridge the gap between active and passive safety evaluations.

Differences in injury risk between females and males are often reported in field data analysis. The aim of this study was to investigate the differences in kinematics and injury risks between average female and male anthropometry in two exemplary use cases. A simulation study comprising the newly introduced VIVA+ human body models (HBM) was performed for two use cases. The first use case relates to whiplash associated disorders sustained in rear impacts and the second to femur fractures in pedestrians impacted by passenger cars as field data indicates that females have higher injury risk compared to males in these scenarios.

Detailed seat models and a generic vehicle exterior were used to simulate crash scenarios close to those currently tested in consumer information tests. In the evaluations with one of the vehicle seats and one car shape the injury risks were equal for both models. However, the risk of the average female HBM for whiplash associated disorders was 1.5 times higher compared to the average male HBM for the rear impacts in the other seat and 10 times higher for proximal femur fractures in the pedestrian impacts for one of the two evaluated vehicle shapes..

Further work is needed to fully understand trends observed in the field and to derive appropriate countermeasures, which can be performed with the open source tools introduced in the current study.

In the abessment of road user and vehicle occupant safety, physical testing is limited to a few scenarios. Virtual testing (VT) offers an opportunity to advance transport safety by introducing additional test cases. The objective of the VIRTUAL project is to provide tools such as finite element models, guidelines and a corresponding platform to foster the uptake of VT. A VT platform, OpenVT, has been established and provides open-source human body models (HBMs) of both an average female and male, seated and standing, as well as a seat, generic vehicle and tram front models. The tool chain from virtual to physical testing has been illustrated in the low severity impact case where the seat evaluation tool was developed. The newly established organisation OVTO will run the OpenVT platform in the future and govern the evolution of the results of the VIRTUAL project after its completion.

A Finite Element model of a generic Laboratory Seat was developed to replicate a physical counterpart used in rear-impact volunteer tests. The Laboratory Seat has a simplified design, developed to facilitate replication in computational models. The seat has a flat rigid base and the seatback consists of four horizontal panels attached to side posts by coil springs. The seat model was validated with results from component tests and sled tests, including the Anthropomorphic Test Device, BioRID II.

An initial test series was carried out to generate data for component validation: the first set of tests to characterise the coil spring properties; and the second set comprising Impactor Tests on Head Restraint Foam to assess the head restraint material properties.

For system level validation, sled tests were conducted both with the empty Laboratory Seat and with the BioRID II. The BioRID II tests were conducted in conjunction with an earlier volunteer test study.

Both the component and the sled tests were reproduced in a virtual environment. Good agreement was achieved between the mechanical tests and the computational simulations.

The seat model is freely available to use: https://openvt.eu/fem/open-access-laboratory-seat-model.

The aim of this study has been to develop new Seat Evaluation Tools (SET)s with the geometries of an average female (50F) and male (50M) as seated car occupants, based on data from humanshape.org. The SETs have been designed to evaluate the occupant protection performances of car seats in a low severity rear impact.

Focus areas have been the motion of the spine, neck and shoulders to enable a human-like interaction with the car seat. Improvements have been made to previous designs of the neck spring and damper system, and a new solution for shoulder flexibility has been implemented. Soft body materials have been used to facilitate the motion of the torso, and a 3D thoracic and lumbar spine design has been developed.

Two physical prototypes, SET v0.1 50F and 50M, have been developed and all drawings and CAD models have been made available under open-source license on the OpenVT platform (https://openvt.eu/). The prototypes have been run in initial dynamic tests and the results have been compared to previous volunteer tests.

This work was carried out within the EU-funded project, VIRTUAL.

Syftet med denna studie har varit att utveckla nya sätesutvärderingsverktyg, Seat Evaluation Tools (SET), med geometrierna för en genomsnittlig kvinna (50F) och man (50M) som sittande fordonspassagerare, baserade på data från humanshape.org. SET har utformats för att utvärdera fordonssätets skyddsprestanda vid en upphinnandekollision i låg hastighet.

Fokusområden har varit rörelsen i ryggrad, nacke och skuldror för att ge en människolik interaktion med fordonssätet. Förbättringar har gjorts utifrån tidigare lösningar för dämpning av nacken och ett nytt koncept för skuldrans rörlighet har implementerats. Mjuka material har använts för att underlätta torsons rörlighet och en bröst- och ländrygg med rörlighet i tre dimensioner har utvecklats.

Två fysiska prototyper, SET v0.1 50F och 50M, har utvecklats och samtliga ritningar och CAD-modeller finns tillgängliga genom OpenVT-plattformen (https://openvt.eu/). Prototyperna har testats i krockprov och resultaten har jämförts med tidigare voluntärtester.

Arbetet har varit en del av det EU-finansierade projektet VIRTUAL.