Crash Safety Presentation

Description

Two Penn State graduate fellows and one Penn State staff member will visit the West Branch Engineering Club to present a unit on Crash Safety. The opening will be a presentation on the full-scale crash testing that regularly occurs at the PTI Test Track near the University Park campus. This will include a discussion of safety concerns as well as video coverage of several of the crash tests. This will be followed by one or two hands-on activities helping students to better understand some of the challenges in making tomorrow’s car safer.

Background Info

GREATT (Graduate Research Education in Advanced Transportation Technologies)

Penn State University and the National Science Foundation have teamed together to provide opportunities for graduate students to become involved in K-12 outreach and to excite K-12 students about science and engineering careers. As a result of this teaming, faculty at the Pennsylvania Transportation Institute (PTI), a research unit under the College of Engineering, have established a program based on the future technologies of transportation. Topics under this umbrella are wide-spread across the disciplines of fuel science, mechanical engineering, electrical engineering, chemistry, industrial engineering, materials science, and even biology.

Activity: Air Bag Chemistry

Become a chemist/engineer—design an air bag that will protect your passenger from injury.

The airbag is an important technological advance that has saved many lives. An air bag is made of coated fabric and is stored in a module mounted to the steering wheel. Crash sensors, which activate upon impact at speeds of 10-15 miles per hour, are mounted in several locations on the car chassis. In a crash, the sensors ignite a chemical, sodium azide (NaN3), which releases harmless nitrogen gas to instantly inflate the bag. As the driver or passenger is thrown into the bag, it applies a restraining force. Even though this entire process happens in only 1/25 of a second, the added time is enough to slow momentum and prevent serious injury.

The engineers who design air bags are able to determine the exact quantity of chemicals needed to inflate the air bag to the proper volume, and in the correct amount of time. If the air bag is under inflated or inflates too quickly, the passenger will still be injured by the steering wheel. If the air bag over inflates or inflates too slowly, the passenger will hit the inflating airbag and be injured. It is critical to get just the right amount of gas in the air bag.

Activity: Crumple Zone

Become an engineer—design a crumple zone to protect your occupants.

Most cars have crumple zones which are designed to crush or crumple when they are hit. This means that the force of a crash is spread throughout the area so that the force applied on the people inside the car is less – protecting them from serious injuries.

Passengers are better protected if a car crumples up than if it keeps its shape during a crash. This is because the crumple zone built into cars collapses and absorbs some of the impact energy. If the car body doesn’t collapse, most of the impact energy is transferred to the passengers, causing greater forces and injuries. The use of crumple zones and seatbelts and greatly reduced the number of deaths on the road.

This manipulative is designed to show some of the impact from a crash can be absorbed by the car rather than the passengers. When the crumple zone collapses, the force on passengers is reduced, so they are more likely to survive.

It is typically believed that modern cars are inferior because they collapse more during crashes. However, this change in car body construction has been introduced to save lives.