Study explores lightweighting potential of structural foam in vehicle bodies

In a joint study, German chemicals company Henkel and engineering consultancy RLE International have examined the potential of high-performance structural foam for lightweighting in automotive body and closure parts. Henkel says the study shows that fiber-reinforced polymer components with structural foam ribbing and reinforcements can save more than 40 kg of weight per car compared to conventional all-metal designs.

The hybrid parts feature a solid frame or carrier molded in
higher percent fiber-reinforced polymers (FRP) and selective reinforcements
using Henkel’s Teroson EP structural foam, a commercially available epoxy-based
material that delivers high strength and stiffness at low weight. The foam is
injected into the carrier at predefined sections, expands in the e-coat oven,
and creates a stiff connection between the hybrid component and adjacent parts
in the body-in-white.

The project studied all major body and closure parts of an SUV, from the bumpers, fenders, pillars and doors to the rocker panel, side panels and tailgate.

The crash simulations performed in the study adhered to international
automotive standards, such as offset and small overlap frontal crash testing as
laid out in the European New Car Assessment Program (Euro NCAP) as well as the
Insurance Institute of Highway Safety (IIHS) at speeds of 64 and 50 km/h, respectively.
The side crash performance was tested according to US NCAP specifications at 32
km/h. The rear impact scenario was simulated with a 60 km/h moving barrier onto
a fixed test vehicle as defined by US Federal Motor Vehicle Safety Standard No.
301.

RLE and Henckel found that the hybrid designs with Henkel’s Teroson EP structural foam passed all these tests well within the limits of deformation and intrusion, while at the same time offering weight savings compared to conventional all-metal designs.

David Caro, Head of Global Engineering at Henkel, said, “The
results of our study have confirmed that we can achieve significant further
weight reductions without compromising the safety in typical crash scenarios by
optimizing the stiffness of fiber reinforced plastic frames or carriers with
selective foam ribbing and reinforcements, with competitive costs.”