Energy Error

RAMGANESH

Dear ALL

 

I am performing the crash analysis ( Roll over) in Radioss , during solving facing the energy error issue which is increasing in -ve percentage.

 

Please provide your guidelines

 

Thanks

RAM

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Altair Forum User

Hi Ram,

 

Negative energy is seen when energy is dissipated from system.  There could be lot of reasons for the same, it could be because of damping or hour glass, etc...

 

 

Review the results and see the whether they are realistic or not. Also try to use physical stabilization to reduce hour glass deformations. 

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RAMGANESH

Dear Prakash,

 

Please find the curve for the respectives ....

 

Thanks

RAM

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Altair Forum User

Ram,

 

Normal hourglass  energy valid upto -15% as per help. Keep the analysis going and review the results at the end. 

Altair Forum User

Ram,

 

Also notice the error is because of a node. Check if the node is involved in contacts.

RAMGANESH

Dear Prakash,

 

Thanks for the support

 

Thanks

RAM

RAMGANESH

Dear prakash,

 

Yes those nodes are involved in contact Type 7

 

Thanks

RAM

Altair Forum User

Hi Ram,

For a node, check the characteristics of connected elements. If the node is on the master side or the slave side of an interface, this interface must be verified. The gap of the interface should be verified. Try with slightly increased Gapmin value and also keep Inacti to 6.

Meanwhile also check for any penetrations in that interface. 

RAMGANESH

Dear George,

 

I have used the values as shown in image for my contact definition Type 7

 

if i changed inacti to 6 it shows error in initial penetration in interface....

 

Please provide your guidelines and suggested the values to be used for Type 7 contact

 

Thanks

RAM

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Altair Forum User

Hi Ram,

Increase Gaping to 0.5 and try running the analysis. Keep the inacti to 6. Import the model into HyperCrash and you can check for the penetrations in the solver interfaces. You can depenetrate the nodes automatically over there. 

Please check the Help Menu on check solver interfaces for HyperCrash also which explains the same.

gopal_rathore

Hi ,

Please find the attached image for energy balance in rollover scenario.

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