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

• Jun
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?f

#### 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?

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?

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

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.

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.

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.

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