Page Comparison

This section provides description for some common terms that will be used throughout the document

• H Point: The theoretical location of the occupant’s hip. This is the pivot point of both the torso and the upper leg. Many dimensions will be relative to this.

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• 5 Point / 6 Point Harness: A seatbelt with 5 or 6 belts in total. It restrains the movement of the occupant more than a 3 Point Seatbelt and is safer

  • 5 Point Harness

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    • 1 & 2: Shoulder Belts

    • 3 & 4: Lab Belts

    • 5: Anti Sub Belt

• 6 Point Harness

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    • Similar setup to 5 Point Harness however Antisub Belt is two separate belts

• Passthroughs: Cutouts in the seat to allow the belts of a 5 or 6 Point Harness to pass through the seat uninterrupted (as shown by the red circles in the image below)

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• Seatback: The portion of the seat which supports the back and shoulders of the occupant

• Headrest: The portion of the seat which supports the head and/or neck of the occupant

  • In race/bucket seats this will be the area above the shoulder belt passthroughs

• Seatpan: The portion of the seat which supports the buttock and upper leg of the occupant

• Bolsters: Protrusions/barriers typically found on the seatback or seatpan of the seat (shown by the red circles in the image below) They keep the occupant centered in the seat during cornering.

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• Undepressed Seat Contour: The shape of the seat cushioning (typically viewed from the side) when no occupant has sat in it

• Depressed Seat Contour: The shape of the seat cushioning (typically viewed from the side) when an occupant is sitting in the seat - causing the cushioning to compress

• ILD/IFD: Acronym for Indentation Load Deflection or Indentation Force Deflection. A test to determine the stiffness of a foam. Manufacturers will typically specify the stiffness of their foam in ILD/IFD

  • In this test a circular flat indenter is pressed against a foam sample of standardized width, length and height. 60 seconds after the indenter has achieved 25% or 50% compression, the force is measured 

  • Higher ILD/IFD values = stiffer foam

  • 25% ILD/IFD is for a 25% compression

  • 50% ILD/IFD is for a 50% compression

  • US measurements are in pounds-force

  • European measurements are in newtons

Widths

[6]

Length:

• Length of seatpan: 440mm [4]

  • Measured along the thigh line from depressed seatback cushion contour to edge of seat

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• Distance between end of seatpan and back of occupant knee: 25.4mm - 101.6mm  [4]

  • After placing occupant model into the seat model, use this measurement to double check if length is appropriate

  • If for some reason the 440mm seatpan length comes into conflict with this measurement,  this measurement takes precedence over the 440mm seatpan length (i.e. change the seatpan length value so that this distance between end of seatpan and back of occupant knee is within 25.4mm - 101.6mm for all occupants who will sit in the seat)