§572.21. Test conditions and instrumentation. — Inbound Citations

(4) Is large enough so that the three-year-old child dummy described in Subpart C of Part 572 can be placed inside the trunk compartment, and the trunk lid can be closed and latched with all removable equipment furnished by the passenger car manufacturer stowed in accordance with label(s) on the passenger car or information in the passenger car owner's manual, or, if no information is provided, as located when the passenger car is delivered. (Note: For purposes of this standard, the Part 572 Subpart C test dummy need not be equipped with the accelerometers specified in § 572.21.)

(1) Mount the head and neck assembly on a rigid pendulum as specified in § 572.21, Figure 15, so that the head's midsagittal plane is vertical and coincides with the plane of motion of the pendulum's longitudinal center line. Attach the neck directly to the pendulum as shown in § 572.21, Figure 15.

(a) When subjected to continuously applied force in accordance with paragraph (b) of this section, the lumbar spine assembly shall flex by an amount that permits the thoracic spine to rotate from its initial position in accordance with Figure No. 18 of § 572.21 (49 CFR part 572) by 40 degrees at a force level of not less than 18 pounds and not more than 22 pounds, and straighten upon removal of the force to within 5 degrees of its initial position.

(b) When impacted by a test probe conforming to § 572.21(a) at 13 fps in accordance with paragraph (c) of this section, the peak resultant accelerations at the location of the accelerometers mounted in the chest cavity in accordance with § 572.21(c) shall be not less than 50g and not more than 70g. The acceleration-time curve for the test shall be unimodal at or above the 30g level and shall lie at or above the 30g level for an interval not less than 2.5 milliseconds and not more than 4.0 milliseconds. The lateral acceleration shall not exceed 5g.

(b) When the head is impacted by a test probe specified in § 572.21(a)(1) at 7 fps, then the peak resultant acceleration measured at the location of the accelerometer mounted in the headform according to § 572.21(b) is not less than 95g and not more than 118g.

(1) The recorded acceleration-time curve for this test is unimodal at or above the 50g level, and lies at or above that level for intervals:

(i) In the case of the head assembly specified in paragraph (a)(1) of this section, not less than 1.3 milliseconds and not more than 2.0 milliseconds;

(ii) In the case of the head assembly specified in paragraph (a)(2) of this section, not less than 2.0 milliseconds and not more than 3.0 milliseconds.

(b) Install one of the triaxial accelerometers specified in § 572.21(a)(2) on a mounting block located on the horizontal transverse bulkhead as shown in the drawings subreferenced under assembly SA 103C 010 so that the seismic mass centers of each sensing element are positioned as specified in this paragraph, relative to the head accelerometer reference point located at the intersection of a line connecting the longitudinal centerlines of the transfer pins in the side of the dummy head with the midsagittal plane of the dummy head.

(i) Align one sensitive axis parallel to the vertical bulkhead and coincident with the midsagittal plane, with the seismic mass center located 0.2 inches dorsal to, and 0.1 inches inferior to the head accelerometer reference point.

(ii) Align the second sensitive axis with the horizontal plane, perpendicular to the midsagittal plane, with the seismic mass center located 0.1 inches inferior, 0.4 inches to the right of, and 0.9 inches dorsal to the head accelerometer reference point.

(iii) Align the third sensitive axis so that it is parallel to the midsagittal and horizontal planes, with the seismic mass center located 0.1 inches inferior to, 0.6 inches dorsal to, and 0.4 inches to the right of the head accelerometer reference point.

(iv) All seismic mass centers are positioned with ±0.05 inches of the specified locations.

(i) Align one sensitive axis parallel to the vertical bulkhead and coincident with midsagittal planes, with the seismic mass center located from 0.2 to 0.47 inches dorsal to, from 0.01 inches inferior to 0.21 inches superior, and from 0.0 to 0.17 inches left of the head accelerometer reference point.

(ii) Align the second sensitive axis with the horizontal plane, perpendicular to the midsagittal plane, with the seismic mass center located 0.1 to 0.13 inches inferior to, 0.17 to 0.4 inches to the right of, and 0.47 to 0.9 inches dorsal of the head accelerometer reference point.

(iii) Align the third sensitive axis so that it is parallel to the midsagittal and horizontal planes, with the seismic mass center located 0.1 to 0.13 inches inferior to, 0.6 to 0.81 inches dorsal to, and from 0.17 inches left to 0.4 inches right of the head accelerometer reference point.

(b) When the head is impacted by a test probe specified in § 572.21(a)(1) at 7 fps, then the peak resultant acceleration measured at the location of the accelerometer mounted in the headform according to § 572.21(b) is not less than 95g and not more than 118g.

(1) The recorded acceleration-time curve for this test is unimodal at or above the 50g level, and lies at or above that level for intervals:

(i) In the case of the head assembly specified in paragraph (a)(1) of this section, not less than 1.3 milliseconds and not more than 2.0 milliseconds;

(ii) In the case of the head assembly specified in paragraph (a)(2) of this section, not less than 2.0 milliseconds and not more than 3.0 milliseconds.

(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 § 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.

(b) When impacted by a test probe conforming to § 572.21(a) at 13 fps in accordance with paragraph (c) of this section, the peak resultant accelerations at the location of the accelerometers mounted in the chest cavity in accordance with § 572.21(c) shall be not less than 50g and not more than 70g. The acceleration-time curve for the test shall be unimodal at or above the 30g level and shall lie at or above the 30g level for an interval not less than 2.5 milliseconds and not more than 4.0 milliseconds. The lateral acceleration shall not exceed 5g.

(1) Seat the dummy on a seating surface having a back support as specified in § 572.21(h) and orient the dummy in accordance with § 572.21(h) and adjust the joints of the limbs at any setting between 1g and 2g, which just supports the limbs' weight when the limbs are extended horizontally forward.

(1) With the dummy seated without back support on a surface as specified in § 572.21(h) and oriented as specified in § 572.21(h), adjust the dummy arms and legs until they are extended horizontally forward parallel to the midsagittal plane. The joints of the limbs are adjusted at any setting between 1g and 2g, which just supports the limbs' weight when the limbs are extended horizontally forward.