Presentation from Nakajima-san (GTR7-07-07):

The focus of the study is to compare certification performance and seat test performance by Madymo simulations. A parameter study was undertaken to tune the model to meet the certification requirements, using a real certification sled pulse as an input to a model of the old “no-HR” certification sled. The model was tuned by modifying the characteristics of the C1-C2, C7-T1 and T1-T12 joints. The pot B characteristics correlated with greater variation in dummy model measurements. This was also true for seat simulations. The results indicate that large variations in certification tests match with large variations in sled tests, and low variation in certification matches low variation in seat tests.

It was reported that the upper neck My is markedly different in both magnitude and timing for “no-HR” certification tests and seat tests. Lower neck loads were not assessed. It was concluded that if variations are induced in injury metrics in certification tests, the same injury value variations are seen in seat tests. It will be possible to reduce seat test variation by reducing certification test variations. A certification test that is closer to seat tests than the “no-HR” test may be required.

It was noted that the earlier presentations identified differences in seat tests that may not have been identified in certification tests, whereas this presentation indicates that the certification test can predict differences in seat tests. Humanetics noted that many differences in seat tests have been associated with differences in certification performance, but PDB have identified one condition that does not seem to be identified during certification.

It was felt that the influence of pin fit seems to correlate well with the type of adjustments made in the simulation study. Dr Ono noted that the simulation study focused on the internal factors that influence the dummy, whereas the PDB study may reveal more about the external interaction with the seat back.

The data will be shared with Humanetics and, together with the PDB information, it may help prioritise which parts of the dummy to focus on.

Mr Lorenz noted that the TEG is collecting data with the intention to tighten the certification corridors. This simulation study indicates that this will be very important.