(1) The shear force (Fx), axial force (Fz), and bending moment (My) shall be measured by the dummy upper neck load cell for the duration of the crash event as specified in S4.11. Shear force, axial force, and bending moment shall be filtered for Nij purposes at SAE Recommended Practice J211/1 MAR95 (incorporated by reference, see § 571.5) Channel Frequency Class 600.

(2) During the event, the axial force (Fz) can be either in tension or compression while the occipital condyle bending moment (Mocy) can be in either flexion or extension. This results in four possible loading conditions for Nij: tension-extension (Nte), tension-flexion (Ntf), compression-extension (Nce), or compression-flexion (Ncf).

(3) When calculating Nij using equation S6.6(a)(4), the critical values, Fzc and Myc, are:

(i) Fzc = 6806 N (1530 lbf) when Fz is in tension

(ii) Fzc = 6160 N (1385 lbf) when Fz is in compression

(iii) Myc = 310 Nm (229 lbf-ft) when a flexion moment exists at the occipital condyle

(iv) Myc = 135 Nm (100 lbf-ft) when an extension moment exists at the occipital condyle.

(4) At each point in time, only one of the four loading conditions occurs and the Nij value corresponding to that loading condition is computed and the three remaining loading modes shall be considered a value of zero. The expression for calculating each Nij loading condition is given by:

(1) The shear force (Fx), axial force (Fz), and bending moment (My) shall be measured by the dummy upper neck load cell for the duration of the crash event as specified in S4.11. Shear force, axial force, and bending moment shall be filtered for Nij purposes at SAE Recommended Practice J211/1 MAR95 (incorporated by reference, see § 571.5) Channel Frequency Class 600.

(2) During the event, the axial force (Fz) can be either in tension or compression while the occipital condyle bending moment (Mocy) can be in either flexion or extension. This results in four possible loading conditions for Nij: tension-extension (Nte), tension-flexion (Ntf), compression-extension (Nce), or compression-flexion (Ncf).

(3) When calculating Nij using equation S6.6(a)(4), the critical values, Fzc and Myc, are:

(i) Fzc = 6806 N (1530 lbf) when Fz is in tension

(ii) Fzc = 6160 N (1385 lbf) when Fz is in compression

(iii) Myc = 310 Nm (229 lbf-ft) when a flexion moment exists at the occipital condyle

(iv) Myc = 135 Nm (100 lbf-ft) when an extension moment exists at the occipital condyle.

(4) At each point in time, only one of the four loading conditions occurs and the Nij value corresponding to that loading condition is computed and the three remaining loading modes shall be considered a value of zero. The expression for calculating each Nij loading condition is given by: