Title 49

SECTION 572.185

572.185 Thorax (upper torso) assembly.

§ 572.185 Thorax (upper torso) assembly.

(a) The thorax assembly of the dummy must meet the requirements of both (b) and (c) of this section. Section 572.185(b) specifies requirements for an individual rib drop test, and § 572.185(c) specifies requirements for a full-body thorax impact test.

(b) Individual rib drop test. For purposes of this test, the rib modules (175-4002), which are part of the thorax assembly (175-4000), are tested as individual units. When subjected to test procedures specified in paragraph (b)(1) of this section, the rib modules shall meet performance requirements specified in paragraph (b)(2) of this section. Each rib is tested at both the 459 mm and 815 mm drop height tests described in paragraphs (b)(1)(v)(A) and (B) of this section.

(1) Test procedure. (i) Soak the rib modules (175-4002) in a test environment as specified in 572.189(n);

(ii) Mount the rib module rigidly in a drop test fixture as shown in Figure U7 in appendix A to this subpart with the impacted side of the rib facing up;

(iii) The drop test fixture contains a free fall guided mass of 7.78±0.01 kg that is of rigid construction and with a flat impact face 150±1.0 mm in diameter and an edge radius of ±0.25 mm;

(iv) Align the vertical longitudinal centerline of the drop mass so that the centerpoint of the downward-facing flat surface is aligned to impact the centerline of the rib rail guide system within ±2.5 mm.

(v) The impacting mass is dropped from the following heights:

(A) 459 ±5 mm

(B) 815 ±8 mm

(vi) A test cycle consists of one drop from each drop height specified in paragraph (b)(1)(v) of this section. Allow a period of not less than five (5) minutes between impacts in a single test cycle. Allow a period of not less than thirty (30) minutes between two separate cycles of the same rib module.

(2) Performance criteria.

(i) Each of the rib modules shall deflect as specified in paragraphs (b)(2)(i)(A) and (B) of this section, with the deflection measurements made with the internal rib module position transducer specified in § 572.189(d):

(A) Not less than 36 mm and not more than 40 mm when impacted by the mass dropped from 459 mm; and,

(B) Not less than 46 mm and not more than 51mm when impacted by the mass dropped from 815 mm.

(c) Full-body thorax impact test. The thorax is part of the upper torso assembly shown in drawing 175-4000. For this full-body thorax impact test, the dummy is tested as a complete assembly (drawing 175-0000) with the struck-side arm (175-3500, left arm; 175-3800, right arm) removed. The dummy's thorax is equipped with deflection potentiometers as specified in drawing SA572-S69. When subjected to the test procedures specified in paragraph (c)(1) of this section, the thorax shall meet the performance requirements set forth in paragraph (c)(2).

(1) Test Procedure. (i) Soak the dummy assembly (175-0000), with struck-side arm (175-3500, left arm; 175-3800, right arm), shoulder foam pad (175-3010), and neoprene body suit (175-8000) removed, in a test environment as specified in § 572.189(n);

(ii) The dummy is seated, as shown in Figure U4 in appendix A to this subpart, on a flat, horizontal, rigid surface covered by two overlaid 2 mm thick Teflon sheets and with no back support of the dummy's torso. The dummy's torso spine backplate is vertical within ±2 degrees and the midsagittal plane of thorax is positioned perpendicular to the direction of the plane of motion of the impactor at contact with the thorax. The non-struck side arm is oriented vertically, pointing downward. The dummy's legs are horizontal and symmetrical about the midsagittal plane with the distance between the innermost point on the opposite ankle at 100 ±5 mm;

(iii) The impactor is the same as defined in § 572.189(a);

(iv) The impactor is guided, if needed, so that at contact with the thorax its longitudinal axis is within ±0.5 degrees of horizontal and perpendicular ±0.5 degrees to the midsagittal plane of the dummy and the centerpoint of the impactor's face is within 5 mm of the impact point on the dummy's middle rib shown in Figure U4 in appendix A to this subpart;

(v) The impactor impacts the dummy's thorax at 5.5 m/s ±0.1 m/s.

(vi) Time zero is defined in § 572.189(k).

(2) Performance Criteria. (i) The individual rib modules shall conform to the following range of deflections:

(A) Upper rib not less than 34 mm and not greater than 41 mm;

(B) Middle rib not less than 37 mm and not greater than 45 mm;

(ii) The impactor force shall be computed as the product of the impact probe acceleration and its mass. The peak impactor force at any time after 6 ms from time zero shall be not less than 5100 N and not greater than 6200 N.

[71 FR 75331, Dec. 14, 2006, as amended at 73 FR 33921, June 16, 2008]