Meeting Interior Head Impact Requirements: A Basic Scientific Approach 2001-01-0469
FMVSS201U is a Federal Regulation intended to reduce head injury of occupants in motor vehicle collisions. Thus far the industry has made efforts to understand and implement measures to pass the specification. Our team has benchmarked current work, developed the fundamental physics, and then tested our theories in the laboratory and in actual vehicles. The Force vs. Deflection Curve (FDC) is the primary tool used to understand performance of a given hit as well as countermeasure (CM) material/structure design. Specific parameters such as the shape, length, and height of the FDC are used as design criteria. Physical limits are presented as well as reasonable expectations of real data. A procedure is presented to design for passing the FMVSS201U test. The intent of this paper is to provide readers with a way to methodically step through the design, test and analysis and thus eliminating a random and expensive attempt to pass the test. The strategy to pass FMVSS201 becomes shaping the FDC so that the area under the curve (which is a constant of 102 J) is as narrow (lower deflection) as possible without exceeding a height of 6.2 kN.