Crumple Zones can be described as areas usually in the internal part of vehicle body designed to crumple or
deform at or above certain energy levels if the vehicle is involved in a collision. This may sound as if crumple zones
increases the danger to the passengers but the fact is that these zones actually increase the level of safety that a
vehicle can offer to passengers.
When a vehicle is involved in a collision it is subjected to what may be referred to as a rapid deceleration
(acceleration is the correct term for a quick increase or decrease in speed but deceleration may be easier to understand
for this explanation) and other forces.
These forces usually transfer from the body of the vehicle to the passengers inside.
The crumple zones can slow down the rapid deceleration. For instance if a vehicle is involved in a frontal collision
the front of the vehicle may still have the sudden deceleration but as specific areas deform on impact the passenger area
will still have a little forward movement before stopping.
The rate of deceleration will not decrease by much but that slight decrease may be enough for the passenger to
safely hit the airbags.
With regard to the other forces that run through the vehicle during an accident some of these forces will be used
to deform the areas designed to crumple. Metal or any stiff material cannot bend without some force being applied to
This means that less forces or energy will reach the passenger compartment to injure passengers or damage the inside
of the vehicle. There are vehicles that have been involved in accidents and the outside of the vehicle looks like it has been
written off and you may have to pay particular to the interior to find signs of damage.
A basic idea of how crumple zones are designed is by using softer materials in certain areas or subframes. Another
method will be to cut grooves along along a shaft or subframe so while the whole thing is still stiff and strong the grooves
allow it to deform at those areas. These designs can be easily implemented in a monocoque chassis
which is used by most vehicles today.
Crumple zones can be considered to be engineered and not just placed into the vehicle, it becomes part of the vehicle design.
These zones should not be able to crumple too easily nor should it be too stiff. Although the front and rear of the vehicle
is usually used the exact areas chosen to be crumple zones are also of importance.
The passenger compartment which is sometimes called a safety cell or safety cage
also works together with the crumple
zones. The crumple zones dissipate the energy of the collision while the safety cage works as a shield around passengers while
the forces are being dissipated.
The areas where crumple zones has little or no effect in protecting passengers is the sides of the vehicle in the area
of the passenger cabin. While crumple zones may not be able to increase safety in this area, they have saved many lives and
prevented countless injuries.