Plastics in Automotive — The Crumple Zone

Plastics in Automotive — The Crumple Zone


To help protect you in an auto accidents,
your car can be equipped with front and sometimes rear crumple zones, that are designed to absorb
the energy of impacts or crashes in a predictable way. Generally, prior to the 1960’s, people
assumed that the stronger the backbone structure of an auto, the safer the car. The truth,
is larger than this. By Newton’s third law, for every action there is always an equal
and opposite reaction. If an object in motion, such as the car and the human beings inside
it, is going 50 miles per hour and hits a wall, the bodies inside will be acted on
by the wall with equal and opposite force. As the crash continues, so does the force
on the wall and the wall’s vibrating force on the bodies. For example, if a solid train
hits a wall, you may think that it only collides once, but recent accelerometer measurements
indicate that the wall pushes back nearly ten times during the collision, even though
the wall is not literally moving. This “crash pulse” can shake a human body around and really
cause some damage. Human beings need something to absorb, not transmit, that energy before
it reaches us. Plastics play a lifesaving role. Recent research shows that designing
automobile front ends with “crushable” composite structures (crumple zones) can help dissipate
Newton’s reverberating energy. Carbon reinforced plastic composites can absorb six to twelve
times the energy of steel yet possess required strength and stiffness at less weight. These
structures absorb energy as they crush. So, engineers try to create a “crush zone” of
these composites to absorb and dissipate violent energy. Today, light weight plastic composite
crumple zones can allow the front of the vehicle to crush predictably, like a semi-solid foam
filled accordion, absorbing much of the impact and giving off energy in the form of bending
plastic or brooming fibers, as opposed to 100 percent pure bone crunching kinetic energy.
Thereby helping to reduce slamming forces upon impacts and help save lives. At the same
time, its lighter weight, saves gas, and therefore greenhouse gas pollution for the car’s entire
life. http://plastics-car.com/Todays-Automobiles/Automotive-Safety/Physics-in-the-Crumple-Zone-2.html

Leave a Reply

Your email address will not be published. Required fields are marked *