I have a doubt about MAWOP calculation in FFS-III burst analyisis of pipelines under internal pressure, considering corrosion metal loss.
Most of MAWOP FEA calculations reported in the literature considers full yielding of the remanent material in metal loss zone as failure criteria. Thus, the Von Mises equivalent stress is compared with a flow stress and defining a MAWOP according to this.
In some analysis yield stress or the ultimate stress are selected as flow stress. However, in my opinion, using Sflow=Sys is very conservative and Sflow=Sult is very non-conservative criteria. Why not use Sflow=1/2(Sy+Sult), for example, as intermidiate failure criteria?.
Thanks!
Most of MAWOP FEA calculations reported in the literature considers full yielding of the remanent material in metal loss zone as failure criteria. Thus, the Von Mises equivalent stress is compared with a flow stress and defining a MAWOP according to this.
In some analysis yield stress or the ultimate stress are selected as flow stress. However, in my opinion, using Sflow=Sys is very conservative and Sflow=Sult is very non-conservative criteria. Why not use Sflow=1/2(Sy+Sult), for example, as intermidiate failure criteria?.
Thanks!