How are traditional automotive technologies in body structures and chassis staying relevant in the EV revolution?
How are traditional automotive technologies in body structures and chassis staying relevant in the EV revolution?
As more and more OEMs pivot towards electric vehicle (EV) product lines, design and engineering service providers must also adapt their offerings to meet the new EV demands on traditional automotive technologies, such as body structures and chassis.
Vehicle range, speed to market, packaging, safety, architecture and manufacturing costs are all key considerations for EV design that require significant preparation. One automotive design and engineering service provider, Contechs, is ready to meet these requirements head-on.
CHALLENGES FACING EV DESIGN
“The EV market is still very turbulent, with sales numbers going through peaks and troughs, according to published statistics,” says Iain Trueman, Electrical and Electrification Director at Contechs. “One area that’s really key is to have quick turnaround, and this is where we see many of our customers will have to be flexible to change. Programmes can’t have the traditional timeline of four years. So, companies need to be flexible with their development and build this in early on. This also leads into speed-to-market, which is really crucial.”
Unsurprisingly, range remains a crucial challenge for OEMs within their EV development journey, from light electric vehicles (LEVs) all the way up to heavy-duty HGVs.
“Range is very much a customer-driven requirement, and OEMs must look at the key considerations they need to take into account in order to improve this, such as how range differs between vehicle types,” Trueman continues. “Companies have tried to fall back on traditional methods used in internal combustion engine (ICE) vehicles, where saving weight was the primary target. But designing for an EV is completely different, and sometimes it can be difficult to get people to think differently and be open to new technologies that are out of their comfort zone. You need to be able to change your strategy for developing these types of vehicles to keep up with the rapid pace of development.”
IMPROVING RANGE
Whilst the development of battery density has played a significant part in increasing EV range thus far, the importance of vehicle efficiency remains a critical area of vehicle development. Contechs has therefore identified three primary areas affecting EV efficiency: powertrain efficiency, aerodynamic drag and vehicle mass.
“Contechs started looking at powertrain efficiency,” explains Trueman. “We looked at rolling resistance and internal resistance of the motors, but also the aerodynamics of the vehicle, which is one of those ‘wins’ that you can get a huge amount of benefit from, for very little. This approach needs to be instigated from the very early beginnings of the development phase, not included as an afterthought at the end of the process.”
Due to the efficiency of EV motors and regenerative braking, aerodynamic performance becomes a more significant factor than mass in EVs, if range is the primary consideration. Based on Contechs’ internal vehicle simulations for an EV SUV, a reduction of 0.1Cd (a measurement of aerodynamic drag) resulted in the same range improvement as a mass reduction of 560kg.
“Boat tailing, wheel and braking geometry, panel sealing and powertrain cooling are all key areas where aerodynamic drag can be reduced,” Trueman says. “We can engineer really small, thin structural areas to bleed pressure and control vortices, design alternative load paths and closed wheels to support aerodynamic optimisation in the early phases that can make huge differences and increase range.”
INTEGRATING COMPOSITES
The advantages of composite materials are being increasingly leveraged to enhance aerodynamics through thin structures, deep draw geometry and optimised stiffness.
“Composites can be used for a lot more than just saving weight,” Trueman offers. “Because they have a fundamentally different structure, you can get composites to do things that your traditional metals and polymers can’t, while being a lot stiffer. However, it’s about understanding the right place and application on the vehicle to use composites, and where they can be used in combination with materials like advanced aluminium alloys and high-strength steels to make big differences. These applications might not always be the ‘sexy’ things everyone likes to shout about – take a wing mirror for instance – but these are often the areas that make the big difference.”
SPEED TO MARKET WITH SIMULATION
Compressed OEM timing plans mean speed to market is crucial, however traditional methods in body and chassis design and manufacture involve long lead-time CAE simulation and physical prototypes. To bypass this challenge, Contechs is researching and deploying topology simulations and deep generative models driven by Large Language Models (LLM) that allow body and chassis engineers to generate over 100 iterations per minute.
“These technologies allow us and our customers to work through design changes much quicker and reduce the back-and-forth of numerous iterations and changes,” Trueman says. “All of these prediction tools allow greater visibility so you can make more informed design decisions earlier on in the process.”
Contechs foresees machine learning algorithms will play a pivotal role in optimising EV designs, and is now working towards implementing these technologies on future projects. These algorithms can analyse vast datasets to consider factors such as material properties, package, crash, and structural performance, and identify patterns and correlations within previous body and chassis data to generate optimised designs. In addition to minimising cost and material usage, this approach could also reduce the number of engineering iterations required to deliver a vehicle programme.
