Development of a Component Head Injury Criteria (HIC ... - FAA

8. EVALUATION OF NHCT TESTS CONDUCTED AT CAMI.
It is generally known that HIC is quite sensitive to input parameters such as head impact angle,
head impact velocity, and impact location. MADYMO models have shown that minor changes
in the input parameters, such as impact angle and velocity, can result in noticeable variations in
the resulting HIC values.
The FSST and NHCT tests conducted at CAMI (table 10) were originally intended to be used on
a one-to-one basis to evaluate the correlation of the resulting HIC values from the two systems.
However, some level of difficulty was encountered in matching the input parameters for both
systems, i.e., the tests were not carried out under identical conditions. This resulted in most of
the FSST parameters having some degree of variation from their corresponding NHCT tests that
would possibly contribute a sizable degree of uncertainty to any one-to-one comparison carried
out as originally envisaged.
In view of this, it became necessary to devise a methodology that would make it possible to
obtain sets of data that could be compared on a one-to-one basis. This was done using a
analytical-experimental modeling process, as outlined in figure 37 and detailed below. This
study also gave an indication of the substantial variations in HIC caused by minor variations in
test conditions.
Correlation
Between
FSST and
NHCT
Obtained
Section 8.5
MADYMO NHCT
Model Used to
Obtain HIC Values
for Input
Parameters
Matched to FSST
Section 8.4
Validated Impact
Target Model
Section 8.2
Validated
MADYMO
Model
Raw Test
Data
Section 8.1
Figure 37. Process Flow for Analytical-Experimental Model
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