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Head Resultant Acceleration

Description​

Head resultant acceleration is the total head-acceleration magnitude across the X, Y, and Z axes [1]. It shows the acceleration intensity without a direction. WebSAT uses this curve to calculate HIC and displays the part of the curve that forms the HIC interval.

This metric does not have a separate button. WebSAT uses resultant head acceleration when you select Injury Metrics > HIC. Head-acceleration data are also used by Vehicle Analysis > NCAP and Component Evaluation > Pedestrian Protection.

Measurements used by WebSAT​

  • Head Linear Acceleration at Head CG (axa_{x}, aya_{y} and aza_{z})

How WebSAT processes the data​

  1. Use a selected resultant head-acceleration measurement, or calculate the resultant from the selected X-, Y-, and Z-axis measurements:
Resultant Head Acceleration=((ax)2+(ay)2+(az)2)Resultant\,Head\,Acceleration = \sqrt((a_{x})^2 + (a_{y})^2 + (a_{z})^2)
  1. If Apply Filter is selected in the HIC settings, filter the source measurements with the selected filter class before calculating HIC.
  2. Convert the resultant curve to g (1 g=9.81 m/s21\:g = 9.81\:m/s^2).
  3. Use the resultant curve to calculate HIC and display the HIC interval.

References​

[1] Huang Z., Zhang B., Wang L., Liu C. "Experimental Study on Side Pole Collision and Deformable Barrier Collision of Car". Journal of Physics Conference Series, 2020 June; 1549(3):032120.