M Burleigh and K Bambach presented a revision of TF-RUCC-1-03 (TF-RUCC-1-03-Rev.1) to inform their findings as well as their proposals.

Slide 4: It was confirmed that inverse corridors were set with the shorter rubber flesh. BGS and BASt insisted that due to the results shown with the longer flesh that the inverse test was more sensitive to leg changes than the pendulum. The inverse test provides more degrees of freedom than the pendulum test because the impactor is completely released during the impact, while the impactor movement is limited due to its fixations at two positions during the pendulum test.

Slides 5 & 6: There were a number of comments regarding the short rubber flesh data. BASt requested the test results, the impactors that have been used, the check up procedure etc. K Bambach is to send out a spread sheet to explain calculations. Inverse values were low and Humanetics will rerun these tests with closer values to the corridors. Chairperson recommended to Humanetics that to review and update Humanetics inverse test rig because quite low data is very strange. It has a chance that a test rig problem.

Slide 7: Humanetics proposed the use of PE sheet to calibrate component sub assemblies as this setup proved to be more stable and repeatable; BASt/BGS would prefer gap condition roller set up as it is more sensitive. M Burleigh stated the setup is very difficult and open to inconsistent results. The fixture has been seen to slide on the top of the roller carriages and rollers can slide rather then roll even when a gap condition is present. The nature of the rollers is very unstable which is why there are stop plates around the rollers. The high movement of the carriage adds to this instability.

The gage sensitivity is still calculated on rollers as the lower travel makes this test more stable than the assembly. Chairperson supported Humanetics proposal to use PE sheet to calibrate component sub assemblies because roller set up is significantly not userfriendly and difficult to handle that to obtain appropriate test data.

Slide 8: BASt and BGS stated the “no gap” test being an unusual calibration setup because it causes unintended friction.

Slide 10: BASt and BGS confirmed this being the usual test setup for e.g. the calibration of load cells.

Slide 11: The conclusion is logical because, as stated by BGS and BASt, the “no gap” test setup causes unintended friction.

Slide 14: BGS and BASt gave an explanation for the observations made during the tests within TF-RUCC-1-05-Rev1: The “with gap” test setup is more sensitive and thus avoids unintended friction, provides a higher degree of freedom, a higher influence on the long bone properties, higher values and a better assessment. Therefore, the higher repeatability of the “PE test” results should not be used as an argument for choosing this type of test, but just the other way round the PE test and the “no gap” test are considered to not being sensitive enough. Therefore, it is again proposed to use the “with gap” test as a calibration test.

Slide 15: Subsequent to the previous comments made, BASt and BGS requested this comparison using the “with gap” method.

Slides 20-21: There was concern over the removal of the outliners for sensitivity calculation on batch 3 and 4 bones. Humanetics had left in the calculation with outliners as that had been previously shown in the earlier presentation (TF-RUCC-1-03) and to help explain the change they were left in. The justification to remove the outliners was; normally bones are flexed 4 times before running the test, in these two cases (by mistake) they were not.

Slide 22: Humanetics stated existing legs would be used for the round robin set up. These legs will have new bones, meniscus, knee springs, bone interfaces, knee cables, bone cables, flesh system and rubber segment buffers. All other parts will be assessed for wear/damage and replaced as needed. It was not possible to supply new legs. It was confirmed that any production legs being made in the assessment time period would have 5 pendulum and 5 inverse tests to add to the data. BASt repeated their concerns that again no brand-new legforms being used to possibly establish shifted or modified corridors, if needed.

Slide 23: J C Kolb confirmed Bertrandt are prepared to run round robin assessment and M Chaka from Ford also offered their services for round robin. O Zander requested that before any round robin testing they need to test two legs to the latest build level to check repeatability and reproducibility as discussed in the IG meeting in Geneva, then round robin should go ahead if results prove satisfactory. Kurt Bambach offered to send Humanetics data showing repeatability on dynamic testing. BASt wondered why the pendulum test being less documented than the inverse test and requested an identical documentation, where applicable.

Slide 24: It was stated that Humanetics would recalibrate the string pots before the round robin to ensure they were to specification. D Gerhring asked if this was necessary. The pots should be calibrated annually anyway and it would be prudent to do this before testing.