The Engineering Design Process
Identify the Problem: The task at hand is to create a helmet that protects an egg from breaking. The helmet must be within the design constraints
- must look like a helmet
- max. circumference = 60cm max height = 20cm
- egg must be visible
- weight limit = 1-kg
- must be made with more than five different materials
Background research:
As our main padding (closest to the egg), we decided to use sponge. We know that sponges can absorb forces and kinetic energy. The Sealed Air company uses lots of different types of foam for packaging. Foam is like sponge in the way that it has lots of give. It is easy to push down and it is very absorbent (of energy). The hard part/base of the helmet is going to be made of styrofoam. Styrofoam is lightweight, but firm at the same time. To prevent breakage of the egg. a layer of sponge and cotton balls will be underneath it. The cotton and sponge will be able increase the time of impact on the right, allowing less of it to reach the egg. Our main goal by using this design is for all of these absorbent materials to greatly lessen the impact so that the egg does not break.
As our main padding (closest to the egg), we decided to use sponge. We know that sponges can absorb forces and kinetic energy. The Sealed Air company uses lots of different types of foam for packaging. Foam is like sponge in the way that it has lots of give. It is easy to push down and it is very absorbent (of energy). The hard part/base of the helmet is going to be made of styrofoam. Styrofoam is lightweight, but firm at the same time. To prevent breakage of the egg. a layer of sponge and cotton balls will be underneath it. The cotton and sponge will be able increase the time of impact on the right, allowing less of it to reach the egg. Our main goal by using this design is for all of these absorbent materials to greatly lessen the impact so that the egg does not break.
Design:
In order to create the most effective and protective helmet, we needed to find materials that would do two things: increase the time and decrease the force of impact. Sponge was the first material we chose to use for the helmet. The sponge would sit on the top of the helmet. We know that sponges can absorb forces and kinetic energy. This would increase the time of impact and possible cause the weight to rebound off of the top, changing direction and moving away from the egg. Underneath the sponge will be a styrofoam dome, which will support the sponge and provide enough upwards force to push the weight away. Inside of the dome, more of the sponge will be placed, along with 2 cotton balls in order to provide cushion in case the weight breaks through the styrofoam. In order to make the helmet more realistic, we will add a pipe cleaner. This will not have any effect on the egg but may keep it from falling out of the helmet if it was not secure enough.
- Materials / Budget / cost
- Rubber Band $5
- 2 Cotton balls $5
- Sponge $20
- Styrofoam $20
- Pipe Cleaner $5
In order to create the most effective and protective helmet, we needed to find materials that would do two things: increase the time and decrease the force of impact. Sponge was the first material we chose to use for the helmet. The sponge would sit on the top of the helmet. We know that sponges can absorb forces and kinetic energy. This would increase the time of impact and possible cause the weight to rebound off of the top, changing direction and moving away from the egg. Underneath the sponge will be a styrofoam dome, which will support the sponge and provide enough upwards force to push the weight away. Inside of the dome, more of the sponge will be placed, along with 2 cotton balls in order to provide cushion in case the weight breaks through the styrofoam. In order to make the helmet more realistic, we will add a pipe cleaner. This will not have any effect on the egg but may keep it from falling out of the helmet if it was not secure enough.
the BUILDING process -
1 - Describe how your helmet protected the egg from cracking. What material was most important in your design? What material that you used was least effective? After dropping the weight on the helmet, it was obvious that the sponge helped greatly, which may have been because it was our most used material. The sponge was able to increase the time of impact and in turn, decrease the amount of damage to the styrofoam underneath it. The least effective material was the face mask. The pipe cleaners did not make a difference to the safety of the egg, but did make it look more like a helmet.
2 - Knowing what you know now, how would you improve upon your designs to make them work better on the next try? Draw a picture if it helps. In order to improve our design, I would make sure to use more of the sponge to cover the styrofoam. This seemed to be our only set back with the construction. The sponge only covered a small portion of the helmet (the very top). It could have been all over the top in order to prevent the slightest damage.
3 - What materials would you recommend that Riddell uses in manufacturing cost effective helmets? The sponge that we used in our helmet was extremely helpful, and overall helped the greatest. Riddell could use more sponge / foam both on the outside and the inside. These materials help to increase time of impact and decrease the force in which players (or possibly a thrown ball) exert. Having this in the inside would be even more helpful if it was on the outside. This is were the impact starts.
4 - The data table shown provides the number of reported concussions over the last 5 years. Create a mathematical model to predict the number of concussions in 2015. Indicate any possible reasons why the number of reported concussions has decreased in the past or will decrease in the future. New discoveries and advancements in equipment have helped scientists and even coaches to understand what is required to keep players safe. This is why concussion numbers have seemed to drop (other than 2010). Because of the education in concussions, I would assume that the number of concussions would drop somewhere around the 130 mark.
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5 - The rising concern among athletic trainers and health advocates (and parents) regarding concussions and multiple concussions among high school football players has prompted numerous studies of the effectiveness of protective head gear and the forces and accelerations experienced by players. One study suggested that there is a 50% chance of concussions for impacts rated at 75 g's of acceleration (i.e., 75 multiplied by 9.8 m/s/s). (The average head impact results in 22 to 24 g's of acceleration.) If a player's head mass (with helmet) is 6.0 kg and considered to be a free body, then what net force would be required to produce an acceleration of 75 g's (~740 m/s/s)? Research g-forces and create a data table of sample g-forces. (Extension: Create a mathematical model of g-force versus time of tolerance.)
f=ma
f=6kg*740m/s =4,440N.
4,440 newtons of force would accelerate a 6kg object to 740m/s/s
f=ma
f=6kg*740m/s =4,440N.
4,440 newtons of force would accelerate a 6kg object to 740m/s/s