Children Attack #2

Please read Tim Baird’s comment to the post “Children Attack” to get the background needed to best understand this entry.

Disclaimer: The following experiment took 18 minutes of company time. As a result, I will work an additional 18 minutes this evening to make up for the time spent doing these tests.

I ended up modeling a quick person, and then I submit that person to a 9000 N force to the face. I took the material of the person as a stiff homogeneous material (nylon), in real life the results would likely be considerably different because a persons body is much more bendy and isn’t made of Nylon. But this will give us a decent feel for what sort of static strain will result from such a blow. My test kid is about 5 feet tall.

Step 1

Step 1 required me to place the model into the FEA program and create a mesh. I used a very coarse mesh because I didn’t want the analysis to take too long.

Step 2

In step 2, I assigned the material Nylon to the body, and then made the feet ‘fixed’ and defined my force to be right in the target’s face. Here I make the assumption that I would be accurate in my assault.

Step 3

Step 3 is simply a screen shot of the running test window.

Step 4

Step 4 shows a graphical representation of the deformation of our test subject. Notice the significant bend resulting from the impact.

Step 5

Finally, step 5 shows the Static strain. Notice the concentrated force in the subject’s neck and left foot (weird…). It is likely that the neck and feet (if they were truly fixed) would be those body parts most damaged by a Roundhouse Kick planted on the target’s face.

9 thoughts on “Children Attack #2

  • 4/12/2005 at 1:59 pm

    wow… just… wow.

    my coworkers were all amused, but they all wonder why the kids feet would be fixed.

  • 4/12/2005 at 4:11 pm

    because they are stooly rat bastards and had to be fitted with concrete shoes and are about to go sleep with the fishes.

  • 4/12/2005 at 4:19 pm

    Um, wouldn’t the subject best be represented by assuming a density of BEEF on a more rigid
    skeletal frame (ie, the nylon). Come on, you know you want to use beef as the material.
    However, nicely done. That is awesome. How come the nose didn’t suffer more deformation?

  • 4/12/2005 at 4:29 pm

    I did a test specifically on the face.

    You’ll notice significantly more damage when the child’s back is ‘fixed’. This would be if I knocked the kid down and then stomped on his face.

    Anyway… there isn’t any damage to the nose because I specifically had the forces act on the jaw.

    That is all.

  • 4/12/2005 at 5:25 pm

    Wouldn’t you have to define Beef as the material? Or is it included in whatever package this sort of testing is done in?

  • 4/12/2005 at 9:41 pm

    That is exactly what happened when I kicked that kid for crying at the movie theater. I mean, honestly. Stupid bastard had it coming. roundhouse to his Nylon face then a little stompy stomp.

  • 4/12/2005 at 10:48 pm


    Hey, I’ve been reading your site for about a month now, and I just had to comment on this post. Awesome. I’m a recent ME grad myself, and when I was going through CATIA Human Task Simulation training, I had some fun with the manikins… but I didn’t do an FEA model. Keep up the good work!

  • 4/13/2005 at 7:23 am

    On a side note. Why don’t you have linked on your sidebar to get more people there, MikeD? Just a thought and suggestion from a valued customer.


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