Engineers use the engineering design process when solving problems. This process was applied to a safety feature called crumple zones. Crumple zones are designed to work together with seat belts and airbags to reduce the impact of a collision on the occupants of a vehicle. Older model cars were made mostly with steel bodies and frames, which made them very strong and sturdy. However, these materials transferred the force of collisions to the occupants inside the vehicle which caused more injuries during collisions. Engineers wanted to make cars safer for occupants during collisions by keeping the strong, steel frames around the passenger compartment of the car but building crumple zones into the front and rear of the car. This way, the car will not crumple into the space where passengers are.
In brainstorming solutions, engineers must identify any criteria and constraints for the solution, taking societal needs and wants into consideration. Criteria are the requirements a solution must meet to be successful. In considering materials for building crumple zones, engineers had to think about how the materials would perform during a collision, which was the main criterion for success. Constraints are limitations on a design. The constraints the engineers had to consider were things like the cost of the material, the strength of the material, the environmental impact of manufacturing the material, and the reliability of the material. The engineers also had to make trade-offs. Making tradeoffs involves sacrificing or losing something to gain something else. The engineers had to trade some features for those that were more important based on considerations such as the availability of sourcing the material.
The materials that showed the most promise for making crumple zones were carbon fiber and aluminum because these materials are strong and they deform in predictable ways. The design and implementation of crumple zones into modern vehicles reduced injuries and death by a significant amount, making modern cars much safer for the occupants.
Complete the activity below to practice applying the engineering design process to the development of crumple zones in cars. Answer each question, then click the question to check your answer.
| 1. How do crumple zones reduce the amount of force on people during a collision? | Crumple zones absorb the force of a collision without transferring that force to the occupants in a vehicle. |
| 2. How did the criteria and constraints affect the design of crumple zones? | Criteria and constraints guided the design of crumple zones. Crumple zones were designed to make cars safer during a collision. The constraints included cost of material, material performance, and material availability. |
| 3. Was the overall design of crumple zones a success? | Yes, the overall design of crumple zones was a success. The rate of injury to occupants of a vehicle during a collision was significantly reduced after crumple zones became standard on vehicles. |
