What Are the Reactions at the Occipital Condyles in a Head Impact Analysis?

  • Thread starter Thread starter mpm
  • Start date Start date
  • Tags Tags
    Biomechanics
Click For Summary

Homework Help Overview

The discussion revolves around a Force Acceleration analysis related to head impact, specifically focusing on the reactions at the occipital condyles when a blow is applied to the chin of a rigid body model of the head. The problem involves calculating forces and moments while neglecting torque.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to apply the parallel axis theorem and considers summing moments about the occipital condyle to find reaction forces. There is uncertainty about incorporating moment of inertia in the absence of torque. Other participants question the necessity of moment of inertia when torque is neglected and seek clarification on the relationship between linear motion and moment of inertia.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the problem and questioning the assumptions made regarding torque and moment of inertia. Some guidance has been offered, but no consensus has been reached regarding the calculations or the necessity of certain parameters.

Contextual Notes

There is mention of an attachment related to the assignment, but the original poster has not included an image in the initial post, which may be affecting the ability of others to provide assistance.

mpm
Messages
82
Reaction score
0
I have a Force Acceleration analysis that I am un sure of. I have a picture of a skull that is punched/kicked/whatever in the chin.

Problem Statement:

The head shown in the figure below is considered a rigid body. IT rocks on the occipital condyle, C, where an axial force, Fa, and a shear force, V, and a neck torque, To, resist the motion. A blow is applied to the chin at point B at an angle of 63 degrees relative to the horizontal. The initial linear acceleration, a, of the mass center, G, is photographically deteremined to be 140 x gravity. For a head of mass 3.5kg, a moment of inertia of 0.0356 kgm^2 about an axis perpendicular to the sagittal plane is calculate.d WHat are the reactions at the occipital condyles if torque To is neglected?


Ive used the parallel axis theorem to find my actual needed inertia.

I am thinking that maybe I need to do a sum of moments about the condyle to find a reaction force, but I'm not sure if that is right or how to do it. I can't figure out how to incoroporate the moment of inertia.

If anyone can help shed some light for me, I would appreciate it.

I will also be around to answer any questions one might have.

Thanks a bunch.
 
Physics news on Phys.org
After doing some research, I have come to the conclusion that if i neglect torque, then I don't even need to worry about moment of inertia. Is this correct? I can't find any equation that relates linear motion with moment of inertia unless there is torque involved.

Is this correct?
 
You may want to put an image on the web, since I don't see any included in your post. Until then, no one will probably be able to help you. :smile:
 
Here is an attachment of what my assignment is.
 

Attachments

  • example.GIF
    example.GIF
    87.7 KB · Views: 680
Last edited:
The answer I came up with is about 9500 N. Is this possible?
 

Similar threads

Replies
7
Views
2K
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
1
Views
4K
  • · Replies 15 ·
Replies
15
Views
6K
Replies
2
Views
8K