HELP: Simulation of auger shaft FEA

[sheehan.p]

Hey guys,

So I've designed up an auger shaft using Inventor 2014 and am now up to the FEA analysis of it. It keeps failing on the simulation becuase apparently it doesn't have enough constraints. What I want to do is to simulate the applied torque of 725Nm and the loading from the materials, 526 Pa on the leading face of the flight, as well as the approximate compressive force. How I constrained it was to to put two pin constraints on it, one at each end on the smaller diameter sections, and a frictionless constraint at the bottom face in the YZ plane. I'm assuming that these constraints will allow the shaft to rotate about the x axis only. 

The simulation is failing though when I apply the forces as it is saying it doesn't have enough constraints. 

Can anyone have a look at see where I'm going wrong? I've attached the file with the constraints and applied forces. I'm fairly new to the simulation side of Inventor so if you can dumb it right down that would be wonderful.

If it makes a difference, this section combines with three others to form the complete auger shaft. If anyone has ideas about the correct way of simulating this, then that would be much appreciated as well. The assembly file that is also attached. 

Cheers.

[admaiora]

Hi,

you have to attach the iam assembly files and the parts files.

Stress analysis can be difficult before understanding completly the parametric software philosophy.

Regards.

[raviburla]

Hi,

Could you please attach the part models as well that correspond to the assemblies? The following parts are missing: Shaft section 1.ipt -> Shaft section 4.ipt and Flight section 1.ipt -> Flight section 4.ipt and few others. The best way to share the model would be via Pack and Go.

There are few reasons why the FEA solver complains about insufficient constraints:

1. The applied constraints don't eliminate all rigid body modes.

2. All the parts are not sufficiently connected by contacts. 

3. Other modeling issues.

If you know that the applied loads are "in balance", then you can turn ON the eliminate rigid body modes option. We will be able to provide more details if you could send the entire model.

Thanks,

Ravi Burla (Autodesk)