Simcenter 3D Solutions How to obtain the vector direction cosines in Simcenter Nastran?
Summary
This article shows how to view the vector directions of min. and max. principal stresses and obtain the direction cosines to calculate the angle.
Details
Simcenter Post can display the vector direction of the stress tensor. Under Edit Post View à Display à set Style to “Line” and Style Options to “Arrow”
The direction cosines and the angle of the vectors aren’t available in Simcenter Post. They would need to be obtained by printing it out either in .f06 or .pch output file. To request this output, under Structural Output Requests, edit the “Output Medium” for Stress output and select PRINT (.f06) or PUNCH (.pch).
Both options print out the stresses for each element and node. Using PUNCH format is recommended as it not only gives a higher precision, especially for cosines, but it is a separate file. The PRINT medium is less precise (rounds the number to 2 decimal places) and increases the .f06 file size significantly, which is mainly used for debugging the FEA output.
Below is a comparison of the two files for a Hex element stress output. In addition, below link for provides output listing for other elements.
https://docs.sw.siemens.com/en-US/doc/289054037/PL20231019720938543.User/id504161
Using these cosines the angle can be calculated.