Presentation from Mr Depinet, Humanetics on the jacket test (GTR7-06-15):

The jacket test uses a Hybrid III 5th female certification impactor, but with tighter tolerance on the radii of the impact surface (all jacket test probes can be used with the Hybrid, but not necessarily the reverse). Preliminary response corridors have been proposed based on a small number of jackets; these will be updated as more data becomes available.

Humanetics Heidelberg recently undertook testing on several jackets and found one jacket that was outlying (the jacket was softer than others). All three dummies passed the no-HR certification, which is part of the reason for wanting to make the corridors narrower. If the jacket fails, it has to be replaced because the jacket cannot be modified.

Mr Hynd asked how much the jacket stiffness could affect R&R testing with very rigid seats – could the reproducibility appear worse than it would be with a standard seat? Also any biofidelity tests with rigid seats may need to be repeated. One of the EEVC biofidelity requirements uses a rigid seat. Mr Depinet presented data from two dummies with soft and stiff jackets in the rigid rally-style seats that were used in the PDB R&R study that was reported previously. Notable differences in upper neck Fx, Fz, My; T1 X-acceleration; and lower neck Fx, Fz, My shape or magnitude were shown.

It was noted that Humanetics have issued a Technical Bulletin to customers recommending that they no longer run the old certification tests; instead they should run the no-HR test for certification (which will also provide data for making the corridors narrower); plus run the with-HR test and jacket test for information. All dummies sent to Humanetics OH and Heidelberg are getting the jacket test and the certification tests as per the draft certification document.

Asked if there was an ageing problem with the jacket Mr Depinet advised that the material would be expected to harden slightly overtime, which is why an annual check has been recommended in the TEG. There should be no problem due to the number of tests that the jacket is used for, provided that it is not torn.

A pin-fit study has been undertaken to evaluate the effect of neck pin interference fit, normal fit, or loose fit in certification tests. The loose pins were ~0.05 mm smaller diameter than standard. The loose fit had less effect than the over-tight fit. It was proposed to use a ‘no-go’ pin test to check for worn holes (giving a loose pin). Also, should be able to insert the pin by hand with no tools, which ensures fit is not too tight. These guidelines will be added to the maintenance checklist located in the user manual. It is recommended that all users check this.