With the increasing demands to improve ride and handling, and CAFÉ requirements, the automakers are faced with evaluating alternative technologies to achieve new competitive standards. In particular, the use of structural foam as a reinforcing media for automotive hollow sections is being examined.
The objective of this study is to examine the use of epoxy structural foam in a hollow section as an optimum reinforcing means, to compare the reinforcing performance of a solid fill versus a laminate configuration, and to determine critical design features that influence performance.
For this comparative study, idealized hat shaped cross sections were physically tested in simple bending and are measured for dynamic stiffness. Beam compliance was measured over a range of input frequencies and was reported for a fully filled and laminate section.
As a parallel study, FEA was conducted for the purpose of correlation, to identify a reinforcing trend, and to establish an analytical tool for the purpose of conducting a sensitivity study.
The FEA sensitivity analysis examined parameters such as reinforcing length, material thickness and material modulus.
The result of this study indicated that reinforcing efficiencies are achieved by not filling a section solid, using a local reinforcement, and laminating a section by use of a polymer layer captured between an inner layer and the parent component.