Autodesk Inventor

[#1]

Hello Everyone,

I'm currently modeling a screw for a spinal implant for my Senior Design project and I am trying to analyze the amount of torque that it can withstand before breaking. I would like to simulate the screw being inserted into bone and see the pressure that the thread undergoes, however, I've only been able to apply forces along the Z and Y axis.

I would appreciate any help regarding this issue. Thank you very much for your time and help.

[#2]

Hi xalan001,

  You can apply a torque load instead of a force, it is labeled as moment.

  I'm not that familiar with bone material, but I assume that the screw threads do not undergo plastic deformation.  It is non-trivial to do a non-linear analysis on threads...as only 2-4 threads hold most of the load at least when we're dealing with metal on metal.

  If you need to include the compliance of bone, I suspect bone may have a non-linear stiffness [Edit: or it is considered a brittle material].  Therefore, this may require Autodesk Mechanical simulation.

Hope this helps...