§572.124. Thorax assembly and test procedure. — Inbound Citations

(iii) 127-2000, Upper Torso Assembly, incorporated by reference in § 572.124,

(1) The maximum sternum displacement relative to the spine, measured with chest deflection transducer (specified in 49 CFR 572.124(b)(1)), must be not less than 38.0 mm (1.50 in) and not more than 46.0 mm (1.80 in). Within this specified compression corridor, the peak force, measured by the probe in accordance with 49 CFR 572.127, must be not less than 1205 N (270.9 lbf) and not more than 1435 N (322.6 lbf). The peak force after 12.5 mm (0.5 in) of sternum displacement, but before reaching the minimum required 38.0 mm (1.46 in) sternum displacement limit, must not exceed an upper limit of 1500 N.

(b) When the anterior surface of the thorax of a completely assembled dummy (drawing 167-2000) that is seated as shown in Figure S1 is impacted by a test probe conforming to 49 CFR 572.127(a) at 6.71 ±0.12 m/s (22.0 ±0.4 ft/s) according to the test procedure specified in 49 CFR 572.124(c):

(1) The maximum sternum displacement relative to the spine, measured with chest deflection transducer (specified in 49 CFR 572.124(b)(1)), must be not less than 38.0 mm (1.50 in) and not more than 46.0 mm (1.80 in). Within this specified compression corridor, the peak force, measured by the probe in accordance with 49 CFR 572.127, must be not less than 1205 N (270.9 lbf) and not more than 1435 N (322.6 lbf). The peak force after 12.5 mm (0.5 in) of sternum displacement, but before reaching the minimum required 38.0 mm (1.46 in) sternum displacement limit, must not exceed an upper limit of 1500 N.

(2) deflection in paragraph (b)(1) of this section must be not less than 65 percent but not more than 85 percent.

(a) The test probe for thoracic impacts, except for attachments, shall be of rigid metal or metal alloy construction and concentric about its longitudinal axis. Any attachments to the impactor, such as suspension hardware, velocity vanes, etc., must meet the requirements of § 572.124(c)(6). The impactor shall have a mass of 2.86 ±0.02 kg (6.3 ±0.05 lb) and a minimum mass moment of inertia of 160 kg-c 2 (0.141 lb-in-sec 2) in yaw and pitch about the CG of the probe. One third of the weight of suspension cables and any attachments to the impact probe must be included in the calculation of mass, and such components may not exceed five percent of the total weight of the probe. The impacting end of the probe, has a flat, continuous, and non-deformable 101.6 ±0.25 mm (4.00 ±0.01 in) diameter face with an edge radius of 7.6/12.7 mm (0.3/0.5 in). The impactor shall have a 101-103 mm (4.0-4.1 in) diameter cylindrical surface extending for a minimum of 12.5 mm (0.5 in) to the rear from the impact face. The probe's end opposite to the impact face has provisions for mounting an accelerometer with its sensitive axis collinear with the longitudinal axis of the probe. The impact probe shall have a free air resonant frequency of not less than 1000 Hz limited to the direction of the longitudinal axis of the impactor.