Modern cars are getting increasingly heavy and this is due to ever more stringent demands in terms of safety and convenience that are being imposed today. To meet these demands, car makers are forced to make their cars more complicated by adding equipment and reinforcing the chassis for added rigidity. Both these approaches inevitably add weight to the vehicle, and this in turn hampers dynamics and performance.
Simply put, the ideal vehicle structure is one that delivers maximum rigidity with the lightest weight, to create the greatest possible strength using the least quantity of materials. In line with the overall SkyActiv philosophy, the new SkyActiv-Body that forms the basis of Mazda’s upcoming generation of vehicles seeks to meet this ambitious engineering goal in order to deliver improved efficiency without sacrificing driving enjoyment.
A strong body structure simultaneously enables a car to be both safer and more enjoyable to drive. In a collision, it is critical that a vehicle’s body structure is able to shield its occupants from the severe forces of impact. A strong body is also more resistant to flexing and vibrations, thus ensuring a comfortable and refined driving experience in which a vehicle feels stable on the move with the three components of Noise, Vibration, and Harshness (NVH) convincingly isolated from the passenger cell.
Yet, there are also equally compelling reasons to keep the weight of a vehicle down, first and most obvious of them being fuel economy. A lighter vehicle requires less energy to move and the benefits from this principle alone are two fold – better performance and reduced fuel consumption. From a dynamics standpoint, a lighter vehicle also has less inertia, and is thus more agile around bends.
What’s truly remarkable about the Mazda SkyActiv-Body is not just how it simultaneously meets these conflicting demands, but also that it does using the best balance of conventional technologies. In other words, the design of this unibody does not involve rocket science of any sort, but extremely intelligent application of what we already know. The Mazda SkyActiv-Body structure is 30% more rigid than its predecessor, yet it is 8% lighter.
A key feature of the SkyActiv-Body is how it manages load paths in its structure. Compared to the existing body structure which contains many curves, bends and discontinuities that become structural weak points, the SkyActiv-Body’s structure frames are connected in a continuous fashion. There is also extensive usage of ring structures and closed section designs that is typically stronger than open-ended structures that are way more easily deflected and distorted.
In addition to optimizing the structure’s overall design, Mazda was also notably more generous in its usage of high-tensile steel to further reduce weight. By investing in a stronger material, Mazda is thus able to deliver comparable, perhaps even better, overall strength compared to the preceding model using a lower volume of materials.
To summarize, the lighter yet stronger SkyActiv-Body delivers enhanced handling and ride comfort, whilst also contributing to improved fuel economy. The improved structural strength of the new bodyshell also guarantees better crash protection thus leading to improved vehicle safety.
Pictures: Official Mazda release.