Rectangular Pressure Vessel
I know this topic has been discussed a lot so please be patient with me
I am designing a rectangular internal pressure vessel using ASME BPV Sect8 Div1 Appendix 13, specifically sketch 6 with chamfered corners and partial reinforcement. I set up a spreadsheet and was pretty happy with the stress figures i got. However to check i set the spreadsheet up correctly i then set my dimensions so the width equalled the height and the type and length of reinforcement was the same (i.e. L3=L4, L2=L1 and L11=L21). With this set-up i was expecting stresses at corresponding points to be equal due to the symetry (i.e. stress @ A = stress @ H, stress @ B = stress @ G, etc.). Most of my points match up [U]except for M and N[/U]
When i look into the equations further i found my value of 'thetaM' [U]exceeds[/U] the value of 'theta1' (theoretically not possible??), and 'betaN' doesn't seem to correspond in any way
I've doubled checked my spreadsheet 100 times, set up a completely new spreadsheet from scratch, and even had a colleague set up his own spreadsheet with no input from me. We both keep getting the same issue.;?
Has anyone else come across similar issues? Can anyone point me in the direction of a solution?
Thanks