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The aim of this study is to use numerical simulations for safety assessment of an innovative active head restraint system. This system was developed to protect the head and neck of an occupant in a car without a head airbag during a side impact. Its FE model is created and embedded it in a model of a small car with a side airbag. The dynamics of the head restraint activation are also taken into account. The virtual human body model Virthuman is used to represent occupants. The model is scaled for pre-selected human individuals to cover large numbers of occupants of different sizes. It extends conventional virtual evaluation of new safety designs via existing pre-defined mono-purpose side dummies and their FE models. The benefit of the head restraint system is evaluated in side impact scenarios inspired by the pole tests performed by EuroNCAP. Transversal impacts to a pole at 29 and 32 km/h are considered at 90° and 75° angles from driver and the opposite side.

The paper concerns the development of a new scalable virtual human body model. The model has been developed to assess safety risk during various complex crash scenarios including impacts from different directions. The novel approach described couples the basic multi-body structure with deformable segments, resulting in short calculation time. Each multi-body structure segment carries the particular surface parts that are linked to the segment with non-linear springs representing the behavior of related soft tissues. The response of particular body segments (head, thorax, pelvis, lower extremities) is validated in known impact scenarios and the response of the model is tuned to the experimental corridors obtained from literature. The tuning process involved the adjustment of both model material and numerical parameters in order to get the correct response for all the tests.

Traffic accidents cause one of the highest numbers of severe injuries in the whole population. The numbers of deaths or seriously injured citizens prove that traffic accidents and their consequences are still a serious problem to be solved. A lot of effort is devoted to both passive and active safety systems development. The transportation standards usually define safety requirements by regulations (e.g. ECE-R94, 96/79/EC and ECE-R95, 96/27/EC in Europe) with specific dummies for children to be used. The dummies include hardware sensors for monitoring accelerations, loads and other signals and each dummy is developed for a specific scenario, but there are limitations of these dummies, such as only a specific age or calibration just for a specific test.

The paper contributes to the development of virtual biomechanical human models as a support for design and optimization of both passive and active safety systems used in various modes of transportation. The paper shows the scaling methodology as simply as possible to creating models based on a reference model regarding anthropology and flexibility. The paper describes the methodology for the scaling of hybrid human models based on a multi-body structure carrying deformable parts. The idea is to have a reference model and to create other models automatically based on the least possible number of parameters. The developed method takes into account the height, age, mass and flexibility of joints. The scaling process starts by scaling the reference model to the target height for given age (including correct height for each major segment of the human body) based on the available anthropometrical data. The scaling coefficient for each segment is also used to scale the segment mass.