Interface results between FEA and FEA NX

Question:

Hi,

Please look attached file and ppt, let me know about the questions.

Thanks

Regards



Answer:

Hi,

1. The difference is caused by an interface calculation method. Old FEA used Newton Cotes rule as an integration method, but FEA NX uses Gauss integration method, so the stress check conditions have changed. In general, this difference may not have caused much difference, but in this model the interface is a compression-only, which affects the stress check conditions of the element, so the results are different. Also, in the stress contour, Newton Cotes rule displays the stresses at the nodes directly, but Gauss integration method displays the stresses at nodes by extrapolation. So, the results are different.

2. 
For old FEA, only the center edge has a non-zero similar stress values, and the other nodes are zero stresses as shown below. Thus, you can see the smooth contour with respect to the center edge.

On the other hand, for FEA NX, the difference in values between nodes in the center edge is somewhat large, and the stress values at the next edge have non-zero values as well as zero values. So it's not as smooth as old FEA. In conclusion, node result differences are the main cause.

Regards,
DK Lee
Technical Manager

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Creation date: 3/23/2020 7:41 AM      Updated: 3/23/2020 5:12 PM
Files   
DataImage17.png
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DataImage91.png
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Interface results between FEA and FEA NX.pptx
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prova interfaccia simmetrica lineare FEA NX_1.rar
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prova interfaccia simmetrica lineare FEA_1.rar
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