Our Goal: To Create a Helmet with sketches and a model
Key Concepts :ACCELERATION is a change in speed over a period of time; the higher the acceleration, the faster the change in speed. For example, if a car goes from 0 miles per hour (mph) to 60 mph in 2 seconds, it is a higher acceleration than if the car goes from 0 mph to 40 mph in 2 seconds. Acceleration is a rate of change of speed; NO change means NO acceleration. If something is moving at constant speed, it is NOT accelerating.
COEFFICIENT OF FRICTION is the measurement of the level of friction embodied in a particular material. The formula is μ = f/N, where μ is the coefficient of friction, f, is the amount of force that resists motion, and N is the normal force. Normal force is the force at which one surface is being pushed into another.
CRUMPLE ZONES are areas of an object designed to deform and crumple in an impact, as a means to absorb the energy of a collision. The fronts of most automobiles are designed as crumple zones to protect the passengers from frontal collisions.
DRAG is a term used in fluid dynamics that is sometimes referred to as air resistance or fluid resistance. Friction is one of multiple factors that influence the amount of drag encountered by a body moving through a fluid such as air or water.
INERTIA: when an object remains still or moves in a constant direction at a constant speed.
G FORCE: a force acting on a body as a result of acceleration or gravity, informally described in units of acceleration equal to one g.
FRICTION is a force that resists motion when two objects or surfaces come in contact.
FORCE causes masses to accelerate; they are influences that cause a change of movement, direction, or shape. When you press on an object, you are exerting a force on it. When a robot is accelerating, it does so because of the force its wheels exert on the floor. Force is measured in units such as pounds or newtons. For instance, the weight of an object is the force on the object due to gravity (accelerating the object towards the center of the earth).
KINETIC FRICTION (or dynamic friction) occurs when two objects are moving relative to each other and rub together (like a sled on the ground).
Helmets are critical for safety in many work environments that can have unpredictable hazards. A good helmet design should be able to protect the brain, but there are many types of helmets meant to cover different scenarios. We decided to take a closer look at hard hats.
Hard hats are designed on a broader scope than other products and as a result, are used extremely often. In fact, you have probably seen one before, even if you haven't realized it (take for instance, passing a construction zone on a road). It is important that helmets meant for construction, engineering, mining, etc. are up to par with the standards of today.
While anything can have improvements over time, hard hats don't have much to improve due to such a universally acclaimed design. Because of this, we used much of our ingenuity and creativity to find a good solution to meet safety, aesthetic, and advantageous requirements. Two items that we really wanted to add to our helmets were built-in work lights and radios. These can help make a job go along more smoothly because it encourages communication, lessens danger, and provides practical items the everyday construction worker needs. When a light is included on the hat, the worker does not need to search all over for a light just to do some work in a duct or under a car or in an attic, and it's the same for the radio. If they are both always on the helmet, then the construction worker will not have to keep track of them, and they can always have an extra hand open. These ideas would help speed up workflow and finish jobs quicker, while also adding ingenuity.
Our helmet also passes safety laws listed https://www.helmets.org/mandator.htm to ensure the safety of our design.
The hard hat is outfitted with an adjustable strap that covers the human occipital bone, providing extra protection directly to that sensitive part of the skull. If the strap is adjustable, more people will be able to use this product. It fulfills laws regarding the use of safety gear in potentially dangerous situations.
There are shock absorber springs between the underlay and the exoshell to increase safety against projectiles and external forces. Since f=ma (force = mass x acceleration), and the mass of an object cannot be magically changed when it's flying towards someone's head, we focused on reducing acceleration. The shock absorber spring technology would deccelerate a body headed to collision, and since acceleration is v/t (velocity over time), it would lessen the impact and prevent damage that could have happened without the shock absorbing springs.
Furthermore, in our design we made sure that the springs can be changed out (unfortunately not shown in the 3D model) so workers could replace older, dying, less-effective ones. These springs would also be sold separately with varying properties, and by changing such properties, we can increase or decrease the friction of the spring. This is important because laws of Kinetic Friction states that Kinetic Energy in the face of an opposing force will convert to Thermal Energy (Entropy). More thermal energy is created while kinetic energy is converted when the spring constant value is increased. Consumers can analyze their degree of potential danger and customize the safety feature of the helmet to suit their physical situations.
The Underlay incorporates all equipment not adhered to the exoshell. This separation between the major components that make up our Hard Hat provides a Compression Zone. Using elasticity to our advantage the Underlay acts similarly to a Crumple Zone in a car.
As specified officially, our design draws many parallels with safe crumple zone engineering concepts. (http://www.honeywellsafety.com/fibre-metal/Head_Protection/?LangType=1033)
Our research: In researching the physics behind helmet design, we learned the numerous aspects that go into the design of a helmet, in order to protect the user. What we found was surprising; construction helmets are very simplistic and lack the modern impact protection mechanisms that bike, skateboard, and motorcycle helmets contain. This is due to a lack of interest in the industry because large construction firms must purchase these safety devices, not individuals who put their own safety paramount, even if it costs them. But these workers safety is still vital. So we researched how the aforementioned helmets with impact protection actually achieve this goal. Most share a similar principle; a hard shell encases a layer of hard foam that will crush on impact. What this does is extend the impact time between your head and whatever surface or oncoming object is heading your way. We can easily see why this works by looking to the equation F=MA with force being F, M being mass, and A being acceleration. In order to minimize the impact, it would be logical that we would want to minimize F (force). To do this then, we would need to minimize either mass or acceleration. Since the mass of you or the object hitting you is constant, then it would only make sense that we would want to reduce acceleration. Once again, we can go to the old physic textbook to find the formula for acceleration: A=ΔV/TΔ. The two variables on the right side of the equation stand for change in velocity and change in time respectively. Once again, we find ourselves with one variable we can’t change (change in velocity), and one that we can (time). If we can increase the duration the head is impacted by the object, we can decrease the acceleration, thereby decreasing the force. This is the simple principle that helmets use to protect their users. Helmets normally do this by implementing hard foam that will crumple on impact. Ideally, this foam will be softer for a light impact and harder for a hard impact. Hard hats specifically have a couple of differences from other types of helmets. Firstly, they are less protective against impact, normally opting for an isolated headband that holds up a hard plastic shell. This is primarily because these hats are made to protect workers from any falling debris, not impact. But what we also found is this is also due to a simple lack of initiative from the companies that make these helmets. Ultimately, without these impact protection features, the workers wellbeing is compromised. The sturdy outer shell we found was also very important. Unlike a motorcycle or bike helmet, hard hats must protect from sharp objects that may fall (think rebar, concrete, wood) so a sturdy shell is essential to make sure these objects do not pierce or indent the skull of the worker. Instead, the impact is distributed, lessening the pressure experienced on any one part of the skull. Given this, the material the shell is made of is vital to the design. What we found is that the material of choice in this application is a material known as high density polyethylene (HDPE). We found that this material is actually the most common plastic used in the united states, and for good reason. The material is strong, lightweight, moldable, impact resistant, long lasting, and resistant to wear. Because of this, we decided to stick to the industry standard in this case, simply because there is nothing to improve.
Sources:
https://www.plasticsmakeitpossible.com/about-plastics/types-of-plastics/professor-plastics-high-density-polyethylene-hdpe-so-popular/
http://zonalandeducation.com/mstm/physics/mechanics/forces/newton/mightyFEqMA/mightyFEqMA.html
http://www.physicsclassroom.com/class/1DKin/Lesson-1/Acceleration
https://www.helmets.org/general.htm
COEFFICIENT OF FRICTION is the measurement of the level of friction embodied in a particular material. The formula is μ = f/N, where μ is the coefficient of friction, f, is the amount of force that resists motion, and N is the normal force. Normal force is the force at which one surface is being pushed into another.
CRUMPLE ZONES are areas of an object designed to deform and crumple in an impact, as a means to absorb the energy of a collision. The fronts of most automobiles are designed as crumple zones to protect the passengers from frontal collisions.
DRAG is a term used in fluid dynamics that is sometimes referred to as air resistance or fluid resistance. Friction is one of multiple factors that influence the amount of drag encountered by a body moving through a fluid such as air or water.
INERTIA: when an object remains still or moves in a constant direction at a constant speed.
G FORCE: a force acting on a body as a result of acceleration or gravity, informally described in units of acceleration equal to one g.
FRICTION is a force that resists motion when two objects or surfaces come in contact.
FORCE causes masses to accelerate; they are influences that cause a change of movement, direction, or shape. When you press on an object, you are exerting a force on it. When a robot is accelerating, it does so because of the force its wheels exert on the floor. Force is measured in units such as pounds or newtons. For instance, the weight of an object is the force on the object due to gravity (accelerating the object towards the center of the earth).
KINETIC FRICTION (or dynamic friction) occurs when two objects are moving relative to each other and rub together (like a sled on the ground).
Helmets are critical for safety in many work environments that can have unpredictable hazards. A good helmet design should be able to protect the brain, but there are many types of helmets meant to cover different scenarios. We decided to take a closer look at hard hats.
Hard hats are designed on a broader scope than other products and as a result, are used extremely often. In fact, you have probably seen one before, even if you haven't realized it (take for instance, passing a construction zone on a road). It is important that helmets meant for construction, engineering, mining, etc. are up to par with the standards of today.
While anything can have improvements over time, hard hats don't have much to improve due to such a universally acclaimed design. Because of this, we used much of our ingenuity and creativity to find a good solution to meet safety, aesthetic, and advantageous requirements. Two items that we really wanted to add to our helmets were built-in work lights and radios. These can help make a job go along more smoothly because it encourages communication, lessens danger, and provides practical items the everyday construction worker needs. When a light is included on the hat, the worker does not need to search all over for a light just to do some work in a duct or under a car or in an attic, and it's the same for the radio. If they are both always on the helmet, then the construction worker will not have to keep track of them, and they can always have an extra hand open. These ideas would help speed up workflow and finish jobs quicker, while also adding ingenuity.
Our helmet also passes safety laws listed https://www.helmets.org/mandator.htm to ensure the safety of our design.
The hard hat is outfitted with an adjustable strap that covers the human occipital bone, providing extra protection directly to that sensitive part of the skull. If the strap is adjustable, more people will be able to use this product. It fulfills laws regarding the use of safety gear in potentially dangerous situations.
There are shock absorber springs between the underlay and the exoshell to increase safety against projectiles and external forces. Since f=ma (force = mass x acceleration), and the mass of an object cannot be magically changed when it's flying towards someone's head, we focused on reducing acceleration. The shock absorber spring technology would deccelerate a body headed to collision, and since acceleration is v/t (velocity over time), it would lessen the impact and prevent damage that could have happened without the shock absorbing springs.
Furthermore, in our design we made sure that the springs can be changed out (unfortunately not shown in the 3D model) so workers could replace older, dying, less-effective ones. These springs would also be sold separately with varying properties, and by changing such properties, we can increase or decrease the friction of the spring. This is important because laws of Kinetic Friction states that Kinetic Energy in the face of an opposing force will convert to Thermal Energy (Entropy). More thermal energy is created while kinetic energy is converted when the spring constant value is increased. Consumers can analyze their degree of potential danger and customize the safety feature of the helmet to suit their physical situations.
The Underlay incorporates all equipment not adhered to the exoshell. This separation between the major components that make up our Hard Hat provides a Compression Zone. Using elasticity to our advantage the Underlay acts similarly to a Crumple Zone in a car.
As specified officially, our design draws many parallels with safe crumple zone engineering concepts. (http://www.honeywellsafety.com/fibre-metal/Head_Protection/?LangType=1033)
Our research: In researching the physics behind helmet design, we learned the numerous aspects that go into the design of a helmet, in order to protect the user. What we found was surprising; construction helmets are very simplistic and lack the modern impact protection mechanisms that bike, skateboard, and motorcycle helmets contain. This is due to a lack of interest in the industry because large construction firms must purchase these safety devices, not individuals who put their own safety paramount, even if it costs them. But these workers safety is still vital. So we researched how the aforementioned helmets with impact protection actually achieve this goal. Most share a similar principle; a hard shell encases a layer of hard foam that will crush on impact. What this does is extend the impact time between your head and whatever surface or oncoming object is heading your way. We can easily see why this works by looking to the equation F=MA with force being F, M being mass, and A being acceleration. In order to minimize the impact, it would be logical that we would want to minimize F (force). To do this then, we would need to minimize either mass or acceleration. Since the mass of you or the object hitting you is constant, then it would only make sense that we would want to reduce acceleration. Once again, we can go to the old physic textbook to find the formula for acceleration: A=ΔV/TΔ. The two variables on the right side of the equation stand for change in velocity and change in time respectively. Once again, we find ourselves with one variable we can’t change (change in velocity), and one that we can (time). If we can increase the duration the head is impacted by the object, we can decrease the acceleration, thereby decreasing the force. This is the simple principle that helmets use to protect their users. Helmets normally do this by implementing hard foam that will crumple on impact. Ideally, this foam will be softer for a light impact and harder for a hard impact. Hard hats specifically have a couple of differences from other types of helmets. Firstly, they are less protective against impact, normally opting for an isolated headband that holds up a hard plastic shell. This is primarily because these hats are made to protect workers from any falling debris, not impact. But what we also found is this is also due to a simple lack of initiative from the companies that make these helmets. Ultimately, without these impact protection features, the workers wellbeing is compromised. The sturdy outer shell we found was also very important. Unlike a motorcycle or bike helmet, hard hats must protect from sharp objects that may fall (think rebar, concrete, wood) so a sturdy shell is essential to make sure these objects do not pierce or indent the skull of the worker. Instead, the impact is distributed, lessening the pressure experienced on any one part of the skull. Given this, the material the shell is made of is vital to the design. What we found is that the material of choice in this application is a material known as high density polyethylene (HDPE). We found that this material is actually the most common plastic used in the united states, and for good reason. The material is strong, lightweight, moldable, impact resistant, long lasting, and resistant to wear. Because of this, we decided to stick to the industry standard in this case, simply because there is nothing to improve.
Sources:
https://www.plasticsmakeitpossible.com/about-plastics/types-of-plastics/professor-plastics-high-density-polyethylene-hdpe-so-popular/
http://zonalandeducation.com/mstm/physics/mechanics/forces/newton/mightyFEqMA/mightyFEqMA.html
http://www.physicsclassroom.com/class/1DKin/Lesson-1/Acceleration
https://www.helmets.org/general.htm
Designs
3D:
Download: https://drive.google.com/open?id=1N3s_rGKH1LuytWbwhL2BYLPnkQIt5i0T
Screenshot:
Download: https://drive.google.com/open?id=1N3s_rGKH1LuytWbwhL2BYLPnkQIt5i0T
Screenshot:
Reflection: I partnered with Brandon Fields, Brian Burrous, and Ky Heon. I think each group member was able to contribute good ideas to the helmet and had their own unique take on it. We were also smart about the assignment and split our work equally; for instance I did the 3D model while another did complete research on the physics of a helmet and two brainstormed the ideas. I think I should have managed my time and carried my weight better, because some things were finished later than my initial goal was.