drk186
Aerospace
- Aug 1, 2009
- 5
Does anyone know how NASTRAN calculates this? I cannot find anything in the Users guide.
I made a really simple cantilever beam with FEMAP/NX Nastran and verified that the maximum beam stress merely reports the following stress: sigma_combined = P/A + Mc/I.
However, is there an additional component that I am missing? I am concerned that there may be some tension, shear interaction that is causing the principal directions to be off axis quite a bit, therefore causing the equation above to be invalid (or incomplete). I do not feel comfortable comparing the max combined beam/bar stress to a yield or ultimate material allowable to compute margins using Von Mises or Max Principal failure theory respectively.
Any thoughts?
Thanks in advance.
I made a really simple cantilever beam with FEMAP/NX Nastran and verified that the maximum beam stress merely reports the following stress: sigma_combined = P/A + Mc/I.
However, is there an additional component that I am missing? I am concerned that there may be some tension, shear interaction that is causing the principal directions to be off axis quite a bit, therefore causing the equation above to be invalid (or incomplete). I do not feel comfortable comparing the max combined beam/bar stress to a yield or ultimate material allowable to compute margins using Von Mises or Max Principal failure theory respectively.
Any thoughts?
Thanks in advance.
