With the increasing demands on automakers to improve crash worthiness, and CAF requirements, 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 and to compare the reinforcing performance of a solid fill versus a laminate configuration and several approaches using steel alone.
For this comparative program, idealized hat shaped cross sections are tested in three point bending. A quasi-static load-deflection curve is reported for each beam type. For crash-worthiness, strength and energy absorption is physically measured for an unfilled baseline beam and reinforced beams with the composite reinforcement in the middle third of the length of the beam.
All beams were modeled using FEA failure analysis for the steel and the foam. Correlation was indicated for failure mode and load-deflection. The correlated model was used to conduct a sensitivity study for the carrier properties, the polymer thickness, and efficiencies using steel reinforcements alone.
The result of this study indicates that section reinforcing efficiencies are achieved by not filling a section solid, using a local reinforcing laminate, and reconfiguring existing sheet metal to create a laminate thereby eliminating the need to add an additional metal reinforcement.