Calculating Stress within Beam

[Alanh3]

I am looking to calculate normal and shear stresses within an assembly I made using Inventor. I need to calculate stresses based on assumed loadings, and I was not sure how to do that. We learned in school to use shear stress = VQ/It + Tc/J and normal stress = P/A + Mc/I, with correct definition of variables to calculate these values. Is this an accepted method in engineering? Or do I need to use some type of software for my calculations? I simply want to calculate these stresses for an assembly used to lower down and unfold a horizontal platform. I just need to know if this method is solid.

Thank you,
Alan

 

[rb1957]

well Inventor has it's own FEA package (which I wouldn't use).

if you're wanting to do hand calcs to verify the design, then sure. I'd simplify it to ...
1) the web needs to carry the shear load (V/dt),
2) the caps carry the bending (M/d/A), and probably the compression cap is critical,
3) buckling/crippling allowables are tricky
4) if torsion, design a closed section, stress = T/(2[A]*t)

another day in paradise, or is paradise one day closer ?