WP3 – Computational modelling
A finite element model of a crash dummy representing an average female will be developed for use in simulations within WP4 and WP5. Furthermore, test data from WP2 will be analysed to set biomechanical response corridors targets.
Update, August 2011
A first version of a finite element dummy model of an average female, called EvaRID, has been developed. EvaRID is based on the same design concept as the 50th percentile male rear impact dummy, the BioRID II. A first version, EvaRID V1.0, was developed in LS-Dyna.
EvaRID V1.0 and BioRID II model.
The dynamic response of EvaRID V1.0 was compared to data from rear impact tests with female volunteers, Figure 1.2. It was found that it is necessary to further adjust the stiffness of the spinal joints in order to fully mimic the motion of the volunteers. In future, the EvaRID dummy model has the potential to be a valuable tool when evaluating and developing seats and whiplash protection systems.
During the reporting period the specifications of the numerical dummy model was completed. In close cooperation with WP1 and WP2 a full set of requirements was defined and reported. This includes:
Model anthropometry: Based on a survey of accident and insurance data
in WP1 it was decided that the model developed in the ADSEAT project should be
a model of an average female. In close cooperation with WP2, a full set of
anthropometric requirements was derived from existing databases. The
requirements were defined such as to allow for scaling down from the BioRID II
dummy model which represents a 50th percentile male.
Biomechanical requirements: An initial set of biomechanical requirements
was collected from literature and from project partners (Chalmers and LMU) whom had previously conducted volunteer tests with female subjects. Project partner Chalmers generated response corridors on the basis of volunteer tests with eight subjects. Humanetics generated a detailed sled model of the set-up to
reconstruct the tests for model validation.
Based on the dummy model specifications the modelling was started by scaling down the existing BioRID II dummy model. Local re-meshing was required to compensate for time step and element distortion effects resulting from the scaling. The model was evaluated under calibration loading conditions, which showed good correlation. Furthermore, overload conditions were applied to check on the model robustness.
Once the first version of the EvaRID was available, detailed evaluation against
biomechanical requirements was made. The first evaluation showed that the model response correlates reasonably well with the test data. However, for final use in the project, further model refinement is needed. As reported in a paper at
the Whiplash 2010 conference (Chang et al. 2010), the stiffness of various
components needs to be fine-tuned.
Mr Paul Lemmen
Humanetics Europe GmbH (Humanetics)