Title 49
SECTION 572.193
572.193 Neck assembly.
§ 572.193 Neck assembly.(a) The neck assembly consists of parts shown in drawing 180-2000. For purposes of this test, the neck assembly is mounted within the headform assembly (180-9000) as shown in Figure V1 in appendix A to this subpart. When subjected to the test procedure specified in paragraph (b) of this section, the neck-headform assembly shall meet the performance requirements specified in paragraph (c) of this section.
(b) Test procedure.
(1) Soak the assembly in a test environment as specified in 49 CFR 572.200(j);
(2) Attach the neck-headform assembly, as shown in Figure V2-A or V2-B in appendix A to this subpart, to the 49 CFR Part 572 pendulum test fixture (Figure 22, 49 CFR 572.33) in either the left or right lateral impact orientations, respectively, so that the midsagittal plane of the neck-headform assembly is vertical and at right angle (90 ±1 degrees) to the plane of motion of the pendulum longitudinal centerline;
(3) Release the pendulum from a height sufficient to achieve a velocity of 5.57 ±0.06 m/s measured at the center of the pendulum accelerometer, as shown in 49 CFR Part 572 Figure 15, at the instant the pendulum makes contact with the decelerating mechanism;
(4) The neck flexes without the neck-headform assembly making contact with any object;
(5) Time zero is defined as the time of initial contact between the pendulum mounted striker plate and the pendulum deceleration mechanism;
(6) Allow a period of at least thirty (30) minutes between successive tests on the same neck assembly.
(c) Performance Criteria.
(1) The pendulum deceleration pulse is characterized in terms of decrease in velocity as obtained by integrating the pendulum acceleration output from time zero:
| Time(ms) | Peakpendulumdelta-V(m/s) |
|---|---|
| 10.0 | −2.20 to −2.80 |
| 15.0 | −3.30 to −4.10 |
| 20.0 | −4.40 to −5.40 |
| 25.0 | −5.40 to −6.10 |
| >25.0 <100 | −5.50 to −6.20 |
(2) The maximum translation-rotation of the midsagittal plane of the headform disk (180-9061 or 9062) in the lateral direction measured, with the rotation transducers specified in 49 CFR 572.200(e) shall be 71 to 81 degrees with respect to the longitudinal axis of the pendulum (see Figure V2-C in appendix A to this subpart) occurring between 50 and 70 ms from time zero;
(3) Peak occipital condyle moment shall not be higher than −36 Nm and not lower than −44 Nm. The moment measured by the upper neck load cell (Mx) shall be adjusted by the following formula: Mx(oc) 1 = Mx + 0.01778Fy;
1 Mx(oc) is the moment at occipital condyle (Newton-meters) and Fy is the lateral shear force (Newtons) measured by the load cell.
(4) The decaying moment shall cross the 0 Nm line after peak moment between 102 ms-126 ms after time zero.
[71 FR 75370, Dec. 14, 2006, as amended at 74 FR 29895, June 23, 2009]