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Crumple Zone
Written by N.N
Source: http://s1.cdn.autoevolution.com/images/news/how-crumple-zones-work-7112_1.jpg
The purpose of Crumple Zones is to absorb the impact of the crash (crash energy) by crumpling upwards and away from the passengers. This means that the passengers will be less likely to be severely affected by the crash directly.
The concept of crumple zones was developed by a Merces Benz engineer Bela Bernyi in the Mid 1950's. Mercedes was granted a patent for crumple zones at around the same time and from there, development and the evolution of crumple zones began.
Crumple Zones are typicaly found at the front and back of a vehicle but can also be found in other areas of a car such as the sides. For crumple zones to be most effective, engineers must consider the weight, size and potential stress of the car. Crumple zones are designed to crumple, hence the name.
How do crumple zones work? Well, before we get into the details, we must consider the physics. A moving object has momentum, which is described as the tendency of the object to keep moving in the same direction. The more momentum an object has, the harder it is to change the direction of the object's movement. So a car moving at a rate of 60km/h is harder to change the direction of movement compared to a car moving at a rate of 20km/h. When a crash occurs, cars are often moving at high speeds and find it hard to change direction therefore it speeds along until a force of equal kinetic energy stops its movement. When the car collides with the aforementioned force, it crumples as it absorbs all of the kinetic energy. This design allows the passengers to not be severely affected by the impact.
In the event of a car crash, the passengers will decelerate rapidly and experience lots of force because of the change in momentum. This also causes injuries and using the work-energy principle, the crumple zone was designed to reduce the impact force on a passenger. If you increase the time the car takes to hit a force with equal kinetic energy to reduce its momentum, you decrease the acceleration of the car. The curmple zones are a factor which increase the time the car takes, ultimately decreasing the acceleration of the car.
Ever since the concept of crumple zones was created in the mid 1950's, there has been a lot of change and investigation to find the best method and area to have the curmple zones. Earlier cars would have frontal and rear crumple zones but after investigation, side crumple zones proved handy in the event of a crash and were then developed as an additional safety feature. Now, driver sand passengers are reliant on crumple zones to protect them from too much impact force in the event of a car crash. They have saved lives.
