Inspiring Lightweight Design in Automotive

13th June 2016 by Richard Yen

This post was originally published on the HyperWorks Insider Newsletter.

The NHTSA CAFE (Cooperate Average Fuel Economy) and the EPA Carbon Dioxide (CO2) Emission regulations (aka, GHGs, Greenhouse Gases) are becoming steadily more restrictive by the year 2025.  GHGs targets are directly correlated with fuel economy regulations.  With so many initiates in improving vehicle performances, Automotive OEMs continue to struggle to meet both government-mandated efficiency goals and customer demands for improved fuel economy.

In the US, for example, the CAFE requirements will increase to 55.8 miles per gallon (mpg) in 2025 – a level no OEM currently meets as of today OEMs fuel economy stands at 37.8 mpg (Figure 1). Similarly tough measurements are expected in the European Union (EU) and China, the world’s largest emitting country, with regards to much stricter (CO2) limits. In the latest discussions on real emissions in drive cycles, Nitrogen Oxides (NOx) regulation and incentives for specific powertrain technologies are set to enforce the need for action. Under these standards, the automotive manufacturers have to look for more aggressive measures to meet these requirements.

 

Figure 1
Figure 1

 

Lightweighting Matters

With tough new fuel economy and emissions standards on the way with additional financial penalties for missing them, OEMs will need to increase their use of lightweight materials in additions. Using lighter materials also reduces a vehicle’s fuel consumption, because it takes less energy to acceler­ate a lighter object. For example, a 10% reduction in vehicle weight can result in a 6%–8% fuel-economy improvement. Similarly, advanced materials increase ef­ficiency by enabling engine components to withstand the high pressures and tem­peratures of high-efficiency combustion regimes. Challenges include cost, cycle time, joint methods, and material predictability.

Advanced high-strength steel, aluminum, magnesium, composites, and other materials are all on the table to fulfill the industry’s safety and lightweighting goals. The multi-material designs use a system approach by placing the best properties of materials at the right places to reducing weight and cost. In addition to improving powertrain efficiency and electrification of vehicles, lightweighting is considered closely related to overall fuel efficiency. Multi-material vehicle designs are often discussed as multiple lightweight materials best option to optimize and lightweight a vehicle.

While Lightweighting can be achieved by the following approaches, there can be challenges:

Efficient design – Focus on a whole system approach to vehicle design, select the right materials, and optimize at the right size in the right places. Design knowledge using new materials and joint methods are required. Global platform consideration could result in sub-optimal lightweight design.

Material selections – Most discussions emphasize the cost, interaction of mixed materials and obtaining property characteristics for crashworthiness and durability simulation earlier in the design stage. Joint methods for mixed material could be challenging.

Manufacturing and Assembly – Long cycle time, reliable supply chain and wider variety of manufacturing processes are the barriers to change.

Ancillary system weight reductions – Suppliers may be under pressure to deliver lighter components with improved performance characteristics.

 

An optimization-driven design approach can substantially reduce weight without compromising on performance. A ‘black-aluminum’ roof design (left) compared to an optimized composite design (right) is shown in the picture.
An optimization-driven design approach can substantially reduce weight without compromising on performance. A ‘black-aluminum’ roof design (left) compared to an optimized composite design (right) is shown in the picture.

 

Challenges and Opportunities

From my recent participation in various lightweighting and composite conferences there have been heavy discussions on building consortiums to share information and finding the roadmap to adopt lightweight materials and technologies. The primary goals of all OEMS are to reduce the costs and cycle time, facilitate fragile supply chain globally, and improve design capability using new materials and increase material failure predictability in the long term.  Challenges provide great opportunities and motivate suppliers with innovation. With vast available solutions provided by suppliers, different OEMs are applying different lightweighting strategies to move forward. For example, BMW heavily invested in Carbon Fiber Technology for the i-Series passenger cell using CFRP (Carbon Fiber Reinforced Polymer). Ford and Jaguar Land Rover (both won the Enlighten Awards in the past years) were implementing full aluminum bodies while using mixed materials such as high strength steel, composite, etc. in applicable areas.

Altair Enlighten Award Recognizes Innovative Achievement in Lightweighting

In order to obtain inspiration within the automotive industry and learn best practices for future lightweighting initiatives, Altair annually presents an award in collaboration with the Center for Automotive Research (CAR). The Altair Enlighten Award recognizes achievements in weight reduction across the automotive industry. From motorcycles to commercial vehicles, innovative lightweight designs are recognized for their contribution weight reduction methodologies.

Nominations are now being accepted for the fourth annual Altair Enlighten Award. The 2016 award program allows nominees to submit entries for lightweighting achievements in two distinct categories: full vehicles and modules. The award will be presented at the 51st annual CAR Management Briefing Seminars in Traverse City, MI on August 1-4, 2016.

Learn more about the Altair Enlighten Award

 

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