[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: 49CFR572.7]
[Page 898-899]
TITLE 49--TRANSPORTATION
CHAPTER V--NATIONAL HIGHWAY TRAFFIC
SAFETY ADMINISTRATION, DEPARTMENT
OF TRANSPORTATION
PART 572_ANTHROPOMORPHIC TEST DEVICES--Table of Contents
Subpart B_50th Percentile Male
Sec. 572.7 Neck.
(a) The neck consists of the assembly shown as number SA 150 M020 in
Figure 1 and conforms to each of the drawings subtended by number SA 150
M020.
(b) When the neck is tested with the head in accordance with
paragraph (c) of this section, the head shall rotate in reference to the
pendulum's longitudinal centerline a total of 68[deg] 5[deg] about its center of gravity, rotating to the
extent specified in the following table at each indicated point in time,
measured from impact, with a chordal displacement measured at its center
of gravity that is within the limits specified. 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 head form in accordance with Sec. 572.11(b) shall not
exceed 26g. 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) minus0.5)
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0............................................................... 0 0.0
30.............................................................. 30 2.6
60.............................................................. 46 4.8
Maximum......................................................... 60 5.5
60.............................................................. 75 4.8
30.............................................................. 95 2.6
0............................................................... 112 0.0
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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 4.
(2) Release the pendulum and allow it to fall freely from a height
such that the velocity at impact is 23.5 2.0 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 rising a-t curve
first crosses the 5g level, t2 at the point where the rising
a-t curve first crosses the 20g level, t2 at the point where
the decaying a-t curve last crosses the 20g level, and t4 at
the
[[Page 899]]
point where the decaying a-t curve first crosses the 5g level.
(iii) t2-t1 shall be not more than 3
milliseconds.
(iv) t3-t2 shall be not less than 25
milliseconds and not more than 30 milliseconds.
(v) t4-t3 shall be not more than 10
milliseconds.
(vi) The average deceleration between t2 and
t3 shall be not less than 20g and not more than 24g.
(4) Allow the neck to flex without impact of the head or neck with
any object other than the pendulum arm.
[38 FR 20451, Aug. 1, 1973, as amended at 42 FR 7152, Feb. 7, 1977; 42
FR 12176, Mar. 3, 1977; 45 FR 40596, June 16, 1980]