Static stress can't solve: require non-zero in field 2

[elanthil793]

Hello,

I was trying to do a statical stress simulation. The mesh & variables solved fine since I can see their values in the error page, but then it gave this error: 

CH-SPACEFRAME-04a-P v15: Simulation Model 1 - Study 1 - Static Stress
_____ 2021-01-21 17:13:22 _____

CH-SPACEFRAME-04a-P v15: Simulation Model 1 - Study 1 - Static Stress
_____ 2021-01-21 17:13:25 _____
134766 T : 100.0% of elements (100.0% of volume)
Face Angle min: 0.0582, max : 178
Dihedral Angle min: 0.0193, max : 180
Worst shape ratio : 7.87e+03 on element 22
Worst aspect ratio : 999 on element 1219, shortest edge: 4.49e-06, longest : 0.11
Lowest collapse ratio : 0.000335 on element 22
Worst Jacobian ratio : 1 on element 1
Base mesh: 253606 nodes, 134766 elements
Solver mesh: 253606 nodes, 134766 elements
Job has finished with errors. Receiving results.
Error: NON-ZERO OR NON-BLANK DATA REQUIRED IN FIELD 2
Cause : The specified Bulk Data entry field required a nonzero (nonblank) value.
Action : Add the correct data to the specified field.
Error: ID OUT OF ALLOWABLE RANGE (0-99999999) IN FIELD 2
Cause : The specified Bulk Data entry or Case Control command referenced an identification number
that is out of the displayed allowable range (0-N).
Action : Change the number to within the displayed range.
Error: ID OUT OF ALLOWABLE RANGE (1-99999999) IN FIELD 3
Cause : The specified Bulk Data entry or Case Control command referenced an identification number
that is out of the displayed allowable range (0-N).
Action : Change the number to within the displayed range.
Error: Solver Error
Error: An error occurred while solving the model.

I solved it locally and I tried with manual materials and the ones in Fusion library. The file is attached.

Thanks for helping

Simeng

[John_Holtz]

Hi Simeng,

The problem is you have more than 1 point mass attached to the same geometry. That does not work.

Even it it would work, the point masses are connected to the geometry using rigid connectors. Because a large percentage of the frame has a rigid connector, there is almost nothing left that is flexible!

Here are my suggestions:

1. Eliminate the ground. It is not needed in the analysis and just makes the analysis larger and takes longer to solve.
2. Create a split on the bottom of each wheel so that you can constraint just a small face on the bottom of the wheel where it makes contact with the ground. 
3. Use "Loads > Remote Force" instead of the point masses. Remote forces do not use rigid links.
4. Depending on what the results look like, you probably do not want to bond the wheels to the axles. Vehicles roll better when the tires can rotate about the axle. 😁 (For the analysis, you want the wheels to remain fix, but you want the axle to rotate inside the wheel so that the frame can bend.)