[Code of Federal Regulations]
[Title 49, Volume 6]
[Revised as of October 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR572.17]
[Page 910-911]
TITLE 49--TRANSPORTATION
CHAPTER V--NATIONAL HIGHWAY TRAFFIC
SAFETY ADMINISTRATION, DEPARTMENT
OF TRANSPORTATION
PART 572_ANTHROPOMORPHIC TEST DEVICES--Table of Contents
Subpart C_3-Year-Old Child
Sec. 572.17 Neck.
(a)(1) The neck for use with the head assembly described in Sec.
572.16(a)(1) consists of the assembly designated as SA 103C 020 on
drawing No. SA 103C 001, conforms to each item specified on drawing No.
SA 103C 002(B), sheet 9.
(2) The neck for use with the head assembly described in Sec.
572.16(a)(2) consists of the assembly designated as SA 103C 020 on
drawing No. SA 103C 001, and conforms to each item specified on drawing
No. SA 103C 002, sheet 9.
(b) When the head-neck assembly is tested in accordance with
paragraph (c) of this section, the head shall rotate in reference to the
pendulum's longitudinal centerline a total of 84 degrees 8 degrees about its center of gravity, rotating to the
extent specified in the following table at each indicated point in time,
measured from impact, with the chordal displacement measured at its
center of gravity. The chordal displacement at time T is defined as the
straight line distance between (1) the position relative to the pendulum
arm of the head center of gravity at time zero, and (2) the position
relative to the pendulum arm of the head center of gravity at time T as
illustrated by figure 3. The peak resultant acceleration recorded at the
location of the accelerometers mounted in the headform in accordance
with Sec. 572.21(b) shall not exceed 30g. The pendulum shall not
reverse direction until the head's center of gravity returns to the
original zero time position relative to the pendulum arm.
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Chordal displacement
Rotation (degrees) Time (ms) (2+.08T) minus0.8)
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0............................................................... 0 0
30.............................................................. 21 2.2
60.............................................................. 36 4.3
Maximum......................................................... 62 5.8
60.............................................................. 91 4.3
30.............................................................. 108 2.2
0............................................................... 123 0
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(c) Test procedure. (1) Mount the head and neck on a rigid pendulum
as specified in Figure 4, so that the head's midsagittal plane is
vertical and coincides with the plane of motion of the pendulum's
longitudinal centerline. Mount the neck directly to the pendulum as
shown in Figure 15.
(2) Release the pendulum and allow it to fall freely from a height
such that the velocity at impact is 17.00 1.0 feet
per second (fps), measured at the center of the accelerometer specified
in figure 4.
(3) Decelerate the pendulum to a stop with an acceleration-time
pulse described as follows:
(i) Establish 5g and 20g levels on the a-t curve.
(ii) Establish t1 at the point where the a-t curve first
crosses the 5g level, t2 at the point where the rising a-t
curve first crosses the 20g level, t3 at the point where the
decaying a-t curve last crosses the 20g level, and t4 at the
point where the decaying a-t curve first crosses the 5g level.
(iii) t2-t1, shall be not more than 4
milliseconds.
(iv) t3-t2, shall be not less than 18 and not
more than 21 milliseconds.
(v) t4-t3, shall be not more than 5
milliseconds.
[[Page 911]]
(vi) The average deceleration between t2 and
t3 shall be not less than 20g and not more then 34g.
(4) Allow the neck to flex without contact of the head or neck with
any object other than the pendulum arm.
(5) Allow a time period of at least 1 hour between successive tests
of the head and neck.
[44 FR 76530, Dec. 27, 1979; 45 FR 43353, June 26, 1980, as amended at
55 FR 30468, July 26, 1990]