Optimal Choice of the Foam Design Parameters in Order to Meet the HIC Index Limit of the FMVSS201 Standard

Automotive designers are dealing with refinement of the passenger compartment interior surfaces in order to satisfy the FMVSS201 standard that prescribes a limit value to the HIC index in specific impact test.

In these experimental impact tests a featureless headform hits against any location of the front passenger compartment of a motor car and the resulting HIC index is calculated.

One possibility of meeting the FMVSS201 standard is to cover the metallic structure with an appropriate layer of foam. To take advantage of this possibility the designer has to make an appropriate choice of the foam density and of the thickness of the foam layer.

A number of FEM simulations have been used to study the role of these two fundamental design variables by means of a complete experimental plane that also permits exploration of the possible interactions of the variables.

Results support the designer in making his choice in order to meet the regulatory requirements.