Hood Areas (FMVSS Proposal)

Description

Hood Areas (FMVSS Proposal) maps the hood regions defined by the proposed FMVSS No. 228 pedestrian head-protection requirements [1]. The proposal is based on UN Global Technical Regulation No. 9 and is adapted to United States conditions [2]. WebSAT shows six regions: Hood Top, Hood Area, HIC Unlimited Area, Child Headform Test Area, Adult Headform Test Area, and Test Area.

When this feature is available

Hood Areas (FMVSS Proposal) becomes available when the active component test meets the requirements.

The active test must meet these conditions:

• The loaded test must be a component test.
• The title or test reference number must contain FMVSS.
• The loaded test must include at least one geometry entry.
• The loaded test does not need channel records. This function uses geometry only, so a test with no channels, or with channels that do not have a usable data status, is accepted.

WebSAT enables Hood Areas (FMVSS Proposal) from the loaded test information. You do not select curves for this feature.

Settings

This feature has no settings. WebSAT reads the geometry and vehicle information from the loaded test.

How WebSAT processes the data

1. Load the available hood geometry and reference-line points.
2. Construct the hood top from the leading-edge, side, and rear reference lines. Each side border starts at its measured leading-edge corner, so a side point recorded forward of that corner does not cut across the hood.
3. Limit Hood Area to the part of Hood Top rearward of WAD 1000 and forward of WAD 2100. Use the reference lines for this area, not their inward offsets.
4. Construct the combined Test Area from the measured 82.5 mm inward offset lines, with the same WAD front and rear limits. Split it at WAD 1700 into child and adult regions.
5. Calculate HIC Unlimited Area as Hood Top minus the combined Test Area. Include separate regions and holes in the area calculation and plot.
6. Report the horizontal projected areas and display the measured boundaries and impact points. If the adult region is empty, the child region is the complete Test Area.

The boundary limits apply at each lateral position. The function retains measured corner and discontinuity points, and draws each discontinuity in its measured order. It does not derive an 82.5 mm offset from the horizontal projection or from the Z coordinate.

WebSAT uses LANDMARK to identify each boundary. The DSRL and PSRL codes identify the driver and passenger sides directly. A generic SRL or OFFSET code needs side or edge information from the point name or identified side boundaries. Points do not need a 100 mm station name. If the code and name disagree, the code is used and a geometry note marks the affected result as provisional. One exception: if the point also repeats a point of the line its name gives, at the same position, it is a mis-coded copy. WebSAT leaves it out of the coded line and adds a geometry note. Geometry without LANDMARK codes uses the point names.

If WAD 2100 is absent, WebSAT uses the rear reference boundaries and marks the areas as provisional. It does not invent the missing line. Other missing required boundaries prevent calculation of the affected regions. Geometry notes identify these conditions and any exchanged side labels corrected from measured coordinates.

This function and Pedestrian Protection (NCAP) read the hood boundaries in the same way. Their area definitions are different. NCAP head scoring does not use the proposed FMVSS inward margins.

How to interpret the results

This function does not calculate HIC or an injury probability. It prepares and reports the geometric regions used by the proposed pedestrian head-protection procedure [1].

Proposed HIC area requirements

• The manufacturer defines any HIC1700 area and supplies its boundaries for the compliance test. If the manufacturer does not define a HIC1700 area, the complete combined test area is treated as HIC1000.
• At least two-thirds of the Hood Area within the combined child and adult test area must be in the HIC1000 area.
• At least one-half of the Hood Area below WAD1700 within the child test area must be in the HIC1000 area.
• Any remaining test area must not exceed HIC1700.
• If two-thirds of the Hood Area is larger than the combined test area, the complete combined test area must meet HIC1000. No HIC1700 area is permitted.
• If there is no adult test area, the child test area becomes the complete test area and all tests use the child headform. Two-thirds of the Hood Area must meet HIC1000 within the child test area, and the remaining child test area must meet HIC1700.

Results

Geometric hood boundaries, WAD lines, test regions, and impact points.

The Pedestrian Hood Summary table lists, for each vehicle, the Hood Area, two-thirds of the Hood Area, the Hood Area below WAD 1700 and one-half of it, and the total, adult, and child test areas. Select a row to update the plot.

The Geometry Notes column gives a short label for each note, for example Side label fixed (2) or No WAD 2100 (provisional). Point to the information icon, or move the keyboard focus to it, to read the full text. The export holds the full text.

The Hood Areas Plot draws the leading-edge (LERL), rear (RRL), and side (SRL) reference lines and the WAD lines. One SRL legend entry shows or hides both sides. Each side line starts at its measured leading-edge corner. A dashed line shows the measured 82.5 mm offset lines that bound the Test Area.

References

[1] National Highway Traffic Safety Administration. Notice of Proposed Rulemaking: Federal Motor Vehicle Safety Standards; Pedestrian Head Protection, Global Technical Regulation No. 9; Incorporation by Reference. 89 FR 76960, September 19, 2024.

[2] United Nations Economic Commission for Europe. UN Global Technical Regulation No. 9—Pedestrian Safety, 2009, as amended.