WRC 107 Analysis - How to calculate Pm ??

Dear all

I am a beginner in Pressure Vessel design. Here, I was studying the detailed WRC Calculations. There are 3 notations which confuses me.
Pm - General Primary memberane stress
Pl - Local primary memberane stresses
Q - Secondary stresses.

I got to understand from WRC calculations that
Pl = Algebraic sum of memberane stresses
Q = Algebraic sum of bending stresses.

Now, I am in a confused state how to calculate Pm.

Kindly help me.

Thanks to all in advance

Regards
Ethanga

Dear all
Let me make the things more clear..

I am analysing WRC on 2:1 semi ellipsoidal dish end. Out put comes like,

1. Rad. memb. stress, P
2. Rad. bend. stress, P
3. Rad. memb. stress, Mc
4. Rad. bend. stress, Mc
5. Rad. memb. stress, Ml
6. Rad. bend. stress, Ml

I have calculated like this,

Pl = 1 + 3 + 5
Q = 2 + 4 + 6

Please help me here,

How to calculate Pm. ????

Thank you all, in advance
Ethanga

Dear all
Please reply me at the earliest. I am in a confused state.

Thank you all, in advance
Ethanga.

Dear all

Please come up

Regards
ethanga

Pm is primary membrane stress (due to internal pressure).

Pm is primary membrane stress due to internal pressure only. You can find out Pm using appendix 1-10 including pressure stress intensity at the opening. or you can simply find out the stress due to pressure using thin wall formula as does by PV-Elite.

Hope it is clear now.


SS