Crashworthy Lightweight Material Solution For Automotive Industry

ANN ARBOR, Mich. — May 25, 2017 — BMW, the National Center for Manufacturing Sciences (NCMS), and the University of Delaware-Center for Composite Materials (UD-CCM) has completed research proving the accuracy of high speed computing for modeling and simulation, to predict the quality and effectiveness of a material that is both lightweight and safety-tested. This effort has demonstrated design, materials, manufacturing, and joining methods for continuous carbon fiber thermoplastics, to meet automotive, industry, and government safety specifications.

This two-year program is a successful government-industry-university partnership that involved regulatory agencies, original equipment manufacturers (OEMs), and materials suppliers from the composite industry.

National Highway Traffic Safety Administration (NHTSA) funded this effort and provided input and guidance throughout the program. NCMS managed the program and ensured target objectives were achieved in a timely manner. Close collaboration with BMW was instrumental in establishing B-pillar performance metrics derived from full-vehicle crash simulations and other design and integrations requirements. UD-CCM provided full range of capabilities in materials selection and evaluation, composite design, analysis and crash simulations, process development and manufacturing, full-scale pillar assembly, and high energy impact testing.

The objective of this study was to investigate the computational tools for the design, optimization, and manufacture of carbon fiber materials for vehicle side frame structures (in this case, B-pillar) subjected to high-velocity side-impact crash loading, and to investigate and demonstrate the appropriateness of simulative methods and tools to adequately predict behavior relevant for the assessment of vehicle safety.

“Using the latest, state-of-the-art tools of high speed computing and data analytics, we have proven the qualities and characteristics of a new lightweight material while maintaining safety requirements in vehicles. In this case, BMW and other automotive companies will benefit but ultimately all industry sectors can use these light, strong, crash-resistant materials for their own manufacturing. And the biggest winner will be the safety of the driving public” NCMS President and CEO Rick Jarman.

“A specific continuous fiber thermoplastic material, Carbon Fiber Reinforced Plastic (CFRP) is a preferred solution for reducing weight while maintaining safety requirements for vehicles. The team used this material to successfully design and impact test a lightweight, all-thermoplastic, continuous carbon fiber composite B-Pillar for automotive applications.” UD-CCM Director Jack Gillespie.

The B-pillar design was spatially optimized for energy absorption, stiffness, and strength while maintaining part producibility and vehicle integration. The resulting B-pillar is 60% lighter than the existing metallic design while meeting BMW safety requirements for the NHTSA FMVSS214 side impact crash.

Benefits discovered include:

  • Validation of state-of-the-art Computer Aided Engineering (CAE) simulation tools for full vehicle to component impact data. CAE simulations mirrored practical test scenarios.
  • Development and demonstration of innovative production methods for multi-material parts including infusion and thermoforming tailored blanks with 3 min cycle times.
    Development and automation of adhesive bonding methods for dissimilar thermoplastic and steel interfaces.
  • Achievement of energy savings through a 100% recyclable infusion system with full recovery of the resin and continuous carbon fiber preform possible.
  • Five (5) full-scale B-pillar assemblies were successfully impact tested under 100% equivalent energy of the side impact crash test scenario at the University of Delaware – Center for Composite Materials demonstrating composite behavior.  All B-pillar test subject performance metrics met or exceeded BMW safety requirements for NHTSA FMVSS214 side impact crash.

Results of this program will be disseminated widely to the automotive industry and the technologies are being evaluated by BMW for future platforms.

Posted May 25, 2017

Source: National Center for Manufacturing Sciences