Ford Performance wanted to showcase innovation on the 2016 Ford Shelby GT350 Mustang by creating a grille opening reinforcement made of carbon fiber.
Ford approached Magna International Inc. to assist in the development of a lightweight GOR concept for the Shelby GT350. BASF was invited by Magna to suggest lightweight material concepts, which resulted in a carbon fiber GOR that was 24 percent lighter than the prior plastic-metal hybrid design. The GOR is manufactured with BASF’s Ultramid® polyamide thermoplastic resin with 20 percent short carbon fiber composition. It is 2.5 pounds lighter than the traditional GOR concept that used metal stampings overmolded with plastic.
Carbon fiber is high performing, provides lightweighting opportunities and has a great aesthetic quality. Typically, the GOR is hidden with a beauty cover. However, due to the appearance of the new part, Ford chose to forgo the beauty cover, contributing to an additional loss of 1.9 pounds bringing the total weight savings to 45 percent. The team of engineers also decided to play up the innovative nature of the carbon fiber part further by molding the words “carbon fiber composite” into the visible frontend of the part.
Since the grille opening reinforcement is used to structurally connect the upper rails and lower frame rails, provide the general shape of the frontend and increase the overall stiffness of the front vehicle body, it was crucial that the carbon fiber GOR maintained its structural performance.
Once Magna created the shape and concept, the supplier along with BASF improved the design and optimized the part through the use of advanced technology, such as topology optimization and BASF’s ULTRASIM® tool. Topology optimization was used to tailor the design for efficient material usage based on multiple vehicle load requirements and a pre-determined package space, while maintaining the attachment scheme.
ULTRASIM is a proprietary material characterization technology created by BASF. It was used to accurately predict the material’s performance with up to 90 to 95 percent accuracy. Other systems rely solely on estimations but with ULTRASIM, the material’s performance is mapped in the simulation technology. This is used to fine tune the design, maximize structural performance and minimize material usage.
“ULTRASIM allows us to design as efficiently as possible,” said Brian Shaner, market segment manager for BASF. “We want to create solutions that help make vehicles lighter, improve performance and contribute to a faster development process. ULTRASIM is a key component of that equation. It enables us to help customers optimize their designs.”
Not only did the tools maximize material usage, but the design also eliminated the need for multiple steel stampings and dies and reduced the injection mold complexity typically associated with traditional plastics-metal hybrid solutions. These efforts helped decrease the capital investment by approximately 70 percent.
The team leveraged Magna’s patented resistive implant welding (RIW) process, which provided an economical and reliable method to structurally bond together two large injection molded parts. The RIW process entails placing a conductive element between the two parts that need to be joined, heating the implant with an electrical current, melting the resin and applying pressure to join the two parts together. The result: a structural component with a cohesive bond and an industry first utilizing the process for a carbon fiber polyamide composite material.
“The predecessor of this part was already a plastic-metal hybrid so to reduce the weight of the part, and quite significantly, is a real achievement,” said Tom Pilette, Vice President of product and process development for Magna Exteriors. “BASF’s material properties and expertise allowed us to take advantage of our resistive implant welding joining method with a carbon fiber polyamide composite material, an industry-first application and a key contributor to the success of our design.”
The automotive industry continues to focus on opportunities for reducing carbon fiber costs to enable further market acceptance of this lightweight filler. This solution is gaining traction in high-end, low -production vehicles. Next step, mass produced models.
