Performance vehicle structures have long made extensive use of composite materials and the new generation of GM’s Corvette Stingray, continues the push.
A key composite component of the new Corvette Stingray is a curved carbon fibre rear bumper beam, created through a bespoke application of radius pultrusion.
Pultrusion specialist Thomas Technik & Innovation (TTI) has collaborated with Shape Corp, the US-based tier-one body components supplier, to manufacture the bumper beam in carbon fibre. TTI developed a highly automated bumper beam production cell, now installed at Shape’s facility in Michigan, reputedly the first and only one of its kind in North American automotive manufacturing.
The process sees optimised fibre and fabric guide systems feed the complex set of reinforcements into chrome plated steel Radius Pultrusion moulds. The line controls a complex set of reinforcements including carbon fibres running from a creel, biaxial, triaxial and stitched unidirectional carbon fabrics – all with glass surface tissues for stabilisation and a better surface finish. The installation is set to deliver an annual production capacity of 70,000 parts.
For GM, what is innovative about the rear bumper beam for the Corvette is the fact that it is a constant radius pultruded part. GM say it’s the first in the automotive industry and the production cell used to create the part at Shape Corp is the first of its kind in North America.
Ken Workinger, a pultrusion process engineer at Shape, says: “It’s very impressive considering the size of the part that comes out. But that is the nature of pultrusion – it’s consolidating a lot of fabrics, getting it to exactly where you want in the part, making sure it stays and then curing the resin. And out it comes in a continuous fashion.”
Workinger says the technology is a “game-changer” in the automotive industry because it’s a continuous process that Shape can cater to the needs of OEM customers very effectively.
Shape engineering manager Toby Jacobson adds: “The great thing about composites is that you can customise. But also, that makes things very challenging. You have an infinite number of possibilities, with different materials and different orientation.”
The Corvette bumper beam project has netted Shape a cluster of industry awards including a supplier innovation award from General Motors itself.
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