# How can I calculate the maximum impact force on the helmet?

• Jun
In summary: Welcome to PF.The maximum force that a bicycle helmet has to withstand is the force that is required to damage the helmet. Withstand, as in remain undamaged?
Jun
I am studying the force that helmets have to withstand. If I drop a 5kg head model and helmet at 1.064m on an anvil and the impact time is 0.005 seconds, how do I get the 'maximum' impact load on the helmet?

berkeman said:
Welcome to PF.

Have you looked into the standard test methods for various helmets? There is no need to re-invent the wheel when it comes to helmet testing, IMO.

Also, what kind of helmets do you want to test? Street bike, dirt bike, skateboard, bicycle, etc.?

Multiple helmet testing resources at Wikipedia: https://en.wikipedia.org/w/index.ph...lmet+testing&fulltext=1&profile=default&ns0=1
I am planning to design a new bicycle helmet using the generative design tool of Fusion360. I posted a question because I needed to know the maximum force that a bicycle helmet has to withstand in helmet test, but I couldn't get it. The helmet experiment is not possible because of the lack of conditions.
Is there a way to get it in this situation?

Is this a homework problem? I ask because you are specifying the duration of impact, which is a direct result of the design of the helmet. Also, for a given impact duration, the maximum impact load depends on the design of the helmet.

An elastic impact will have higher peak force than a plastic (constant force) impact. Can you explain why?

Jun said:
I am planning to design a new bicycle helmet
Then the specific Wikipedia article on bicycle helmets (out of the full list of different helmets that I posted) should help: https://en.wikipedia.org/wiki/Bicycle_helmet

jrmichler said:
Is this a homework problem? I ask because you are specifying the duration of impact, which is a direct result of the design of the helmet. Also, for a given impact duration, the maximum impact load depends on the design of the helmet.

An elastic impact will have higher peak force than a plastic (constant force) impact. Can you explain why?
It's not homework. I am a student majoring in design, and I want to design a new helmet shape. I asked because I don't know much about engineering. I specified the duration of impact as 0.005 because I thought it is easier to answer if the conditions are clearly given.

Jun said:
It's not homework. I am a student majoring in design, and I want to design a new helmet shape.
Per the PF rules, schoolwork projects should be posted in the Homework Help forums. I'll move your thread there now, leaving a redirect link behind in this technical forum.

Jun said:
the maximum force that a bicycle helmet has to withstand
Withstand, as in remain undamaged? Helmets are designed to be damaged (plastic deformation) since that minimises the impulse transferred to the head as well making the force profile flatter.

nasu, malawi_glenn, Lnewqban and 1 other person

## 1. How do I calculate the maximum impact force on a helmet?

To calculate the maximum impact force on a helmet, you will need to know the mass of the object hitting the helmet, the velocity of the object, and the time it takes for the impact to occur. You can then use the formula F=ma to calculate the force.

## 2. What is the importance of calculating the maximum impact force on a helmet?

Calculating the maximum impact force on a helmet is important because it helps determine the level of protection the helmet can provide. This information can be used to improve helmet design and ensure the safety of the person wearing it.

## 3. How does the material of the helmet affect the maximum impact force?

The material of the helmet plays a crucial role in determining the maximum impact force it can withstand. Materials with higher strength and impact resistance, such as carbon fiber or Kevlar, can withstand higher impact forces compared to materials like plastic or foam.

## 4. Are there any standards for maximum impact force on helmets?

Yes, there are standards set by organizations such as the Department of Transportation (DOT) and the Consumer Product Safety Commission (CPSC) that determine the maximum impact force a helmet can withstand. These standards ensure that helmets meet certain safety requirements.

## 5. How can I test the maximum impact force on a helmet?

The maximum impact force on a helmet can be tested using specialized equipment such as an impact test machine. This machine simulates real-life impact scenarios and measures the force exerted on the helmet. It is important to follow proper testing procedures to ensure accurate results.

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