ERROR - 6112 in Optistruct

Raja_21933

ERROR MESSAGE --> ERROR # 6112 -- The normal vector is undefined/ambiguous for grid 511180 referenced by ERPPNL/PANELG rrfloor.  This grid may belong to pairs of elements with normals facing opposite directions.

SOFTWARES USED --> Pre-processing - ANSA, SOLVER - Optistruct 2022.2 (running on HPC)

LOADCASE --> ERP Panel participation, SOL - Modal Frequency Analysis

1) How to debug this issue? as there seems to be no elemental quality at the mentioned grid/s

2) Can this error, be checked beforehand with Optistruct - Check?  If so, how can it be done on HPC?

3) Why this error does not occur, when using MSC Nastran, but only occurs when using Optistruct?

Looking forward for your help and suggestions.

Thanks and Regads,

Raja Raghava Sreepathy

Kranzeder

Dear Raja

1) I assume that shell elements have opposite normal directions. Please check and correct

2) Please try running this file in Optistruct with run option -check or you can use the keyword CHECK in the IO section of your .fem file.

3) Maybe MSC Nastran uses a different approach or in worst case it simply does not detect the issue at all.

 

KR Juergen