When mechanics and experts talk about car collisions, the crumple zone is often referred to. This is an important part of car design, yet many drivers are not aware of it. Here, we will explore what the crumple zone is and how it can benefit you in the case of an accident.
In short, the crumple zone does as the name implies - it is part of the car designed to crumple. Yet, more specifically, it is fairer to say this is the car that is meant to be crumpled, as doing so actively improves the overall safety of the driver.
When did crumple zones first appear?
The very first crumple zone was designed in 1959. This was the idea of Béla Barényi Austrian-Hungarian, an engineer employed by Daimler-Benz, now more commonly known as Mercedes-Benz or Mercedes. As far as vehicles are concerned, one of the earliest models to feature such a safety design is the 1953 Mercedes Ponton or W120.
The patent itself, however, was granted in 1952, although the first car to feature this specific design was the Mercedes W111 in 1959.
How do crumple zones work?
While the design and implementation techniques have changed over the years, the concept behind Béla Barényi initial idea has not. Barényi wanted to see if certain parts of the vehicle - specifically, the front and rear, could be built in such a way to absorb kinetic energy.
Consequently, the midsection of the car is often referred to as the passenger cell or safety cell. This is the section that the crumple zones physics serve to protect.
An example of a crumple zone keeping the passenger cell safe from collision.
This is important during a crash. As mentioned previously, sudden braking or stopping can cause a wave of kinetic energy. In the case of collisions, this can cause objects, such as walls and other vehicles, to push into your car, risking harm to you and your passengers. The crumple zone serves to absorb this energy, preventing harm as much as possible.
Originally, this design revolved around longitudinal components. These were supported by supports at the front and rear end of the vehicle, curved to encourage physical deformation, rather than passing the full kinetic energy of a collision into the safety cell.
Further designs included additional ribs, both horizontally and vertically, to help create a shock-absorbing ‘cage’ around the passenger cell. In this way, what cannot be absorbed can potentially be redistributed, preventing any particular build up of energy.
How does this affect the car?
As you might have guessed by the name, crumple zones in cars still take on a lot of damage. In most cases, this is unrepairable. Yet it is better to replace your car then suffer extensive injuries during a collision.
In many ways, you could consider the crumple zone to be similar to the suspension system, as it absorbs forces that you don’t want to disturb the rest of the vehicle. Yet, just as enough shocks and potholes can damage your suspension, a crumple zone isn’t designed to resist impact after impact.
Depending on the force of the impact, the can sometimes be repaired.
Naturally, many drivers are concerned about their engine, which is typically found in the front of the vehicle. However, the crumple zone is based around a mixture of parts that do and do not resist the force of the impact, using the latter as a final layer of protection.
Engines fall into this category, as their hard, durable design does not bend easily, making them very resistant and useful absorbers. Since they are not actively involved, in most cases, your car wheels and tyres will also be uneffected.
After a collision the possibility of repair depends on both the force of the impact and the design of the respective system. The large steel or aluminium parts of the car, such as the engine and framework, are designed to withhold any damage, while other parts are designed to be crumped and will need to be replaced, if possible. As a result, while the crumple zone may very well keep you safe from harm, it does not guarantee the car will remain in a drivable state.
In extreme cases, when the bodywork is severely damaged and even the engine and framework have been unable to resist the complete impact, the car might be beyond repair.
Crumple zones in motorsport
Needless to say, crumple zones are very important in motorsports, and the well thought-out design of such a system has been accredited to saving a driver’s life more than once. Crumple zones are vital, as the higher speeds and competitive nature of racing make high impact collisions, with great kinetic forces, a very possible occurrence.
Similarly, throughout racing history, there have been attempts to decrease the impact from the track itself. While car on car collisions won’t be affected, many tracks often experiment with foam padding or old tyres around walls and corners of the track. The idea here is that these softer materials will help to further lessen the blow, passing less energy onto the crumple zone in the first place.
Motorsports, such as Formula 1, actively use softer border materials and open spaces to help lessen the impact.
This is also why, where possible, corners often have large open expanses of rough terrain before the barrier. In the case of steering out or something else going wrong, this terrain, unlike smooth tarmac, will offer rolling resistance, helping to slow the vehicle down before impact.
How can you improve this?
In short, the crumple zone is built-in to all modern car designs and is not something you can change. That being said, it does still rely on driving physicals, which you can be used to improve the usefulness of the crumple zone.
Specifically, Newton’s Second Law of Motion defines force as mass x acceleration. As such, a faster speed has more force. Likewise, less acceleration will result in less force. As a result, a crumple zone doesn’t just absorb the force, it actively seeks to decelerate the vehicle to lessen the forces exerted on the vehicle as a whole.
A good car tyre, with a thick tread, will help improve braking and deceleration.
Since deceleration is important, quick and reactive braking times will also help improve this. Today, many vehicles feature automatic braking systems for this purpose. Of course, there are situations where braking ahead of time simply isn’t possible. Yet, even here, high quality car tyres could still help improve efficiency.
Specifically, strong grip will help keep the car connected with the road. It goes without saying that this will also depend on the weather conditions at the time. Wet weather can cause aquaplaning, which creates a layer between the tyres and road, which will negate this usefulness. Likewise, in more severe weather, winter tyres ensure good grip, which certainly proves valuable in these circumstances.