A collaboration has resulted in the development of a high-quality stabilizer bar for trucks and trains that is 30 percent lighter than the ones currently on the market.
The AMRC Composite Center worked with Sheffield based Tinsley Bridge and Performance-oriented solutionsin Rotherham, on the Lightweight Metal Composite Hybrid (LiMeCH) project which, with £400,000 in funding from Innovate UK, created a lighter alternative to the tubular steel rod currently used for suspension units.
“Lightweighting is at the top of our clients’ agendas,” said Russell Crow, director of engineering at Tinsley Bridge. “That’s all the more true when they look at alternative propulsion systems, such as electric powertrains and alternative fuels, because every gram they can save makes up for the extra mass they have to carry for the batteries or hydrogen tank.”
In the two-year LiMeCH project, the consortium wanted to create a suitable connection between a composite tube and a metal end fitting that together form a stabilizer bar (ARB).
Crow said the joint must be able to transfer at least the same loads as the equivalent part made from steel spring.
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“The key was to find a modular system,” he said in a statement. “This project wasn’t about making a very expensive composite part, but how we could bond metals and composites together to create high configurability from a small number of stock parts.”
Tinsley Bridge previously collaborated with the AMRC on the development of a metal and carbon fiber reinforced plastic (CFRP) hybrid composite roll bar, bonded with an adhesive, in the Lightweight Composite Suspension Components (LiCoSuCo) project.
Craig Atkins, a research engineer at the AMRC Composite Center, said that while that project made progress in volume composite manufacturing, metal arm manufacturing and bonding, it created other problems that needed solutions.
He said: “We have taken results from LiCoSuCo that have failed, especially with the integrity of the bonded connection between the metal and carbon fiber. The continued LiMeCH project builds on the results of the previous project and continues the collaboration and continue the investigation.”
Performance Engineered Solutions (PES) designed the ARBs, using Finite Element Analysis (FEA) to simulate the pre-fabrication process to determine if the proposed designs can withstand the loads an ARB is exposed to.
Stefan Dalberg, senior design engineer at Performance Engineered Solutions, said: “We had to consider the ease of fabrication, choice of material, choice of adhesive and how it would perform during non-destructive testing (NDT).”
The AMRC’s Composite Center produced four anti-roll bar prototypes using the MF Tech filament winding system. PES thoroughly inspected the inside of the bar with a CT scanner, then used an internal light scanning system to visually inspect the parts.
Crow said the prototypes were then subjected to rigorous testing.
“Inspection of the composite system was critical as these parts have different failure modes than the traditional steel that everyone in the industry knows, understands and is very comfortable with,” he said. “We researched and developed a whole range of non-destructive testing techniques, both in situ and on a test track, to understand whether the part was damaged, the extent to which it had deteriorated and whether it was suitable for continuous use or not. †
Dalberg said non-destructive testing means the consortium can now claim they can bond metals to composites in a way that meets industrial fatigue requirements.