B31E/ Dynamic design by analysis

Posted by: Lesstress

B31E/ Dynamic design by analysis - 11/04/16 10:47 AM

All,
In addition to B31.3, I have been requested to evaluate the seismic stresses based on B31E Code.
I'm ruining the latest version of Caesar software and as you may know , the B31E code has not been addressed directly in the software. I'm looking to build a set of load cases and allowable stresses per section 3.4 of B31E. Is this something that I can do in the software or I have to calculate the stresses and allowable limits manually and compare. Any suggestions for the appropriate load cases?

P.s. : On the case I'm working on, I'm dealing with both inertial forces and Pseudo-static anchor displacements.

Your inputs are much appreciated!

Thanks,
MYJ
Posted by: Dave Diehl

Re: B31E/ Dynamic design by analysis - 11/04/16 12:16 PM

There are two stress evaluations listed in Section 3.4. The first one is very close to the standard sustained plus occasional check found in B31.3. You will have to ensure that the B31.3 sustained stress intensity used in CAESAR II is equivalent to the older, (0.75i) still referenced in B31E. The maximum allowed stress for this check is not 1.33Sh as in B31.3 so you will have to check the limit by reviewing the calculated stresses or tweak the CAESAR II input to give the limiting stress that you wish. CAESAR II does not perform the second stress check where the resulting (force/area) caused by seismic anchor motion is limited by material yield stress at temperature. But you can send the CAESAR II forces and moments report out to MS Excel and SRSS those loads there, then divide that by the (corroded) area and compare the result to SYMS at temperature.
Posted by: Lesstress

Re: B31E/ Dynamic design by analysis - 11/04/16 02:51 PM

Dave,
Thank you very much for your valuable inputs.