ductile failure of anchor bolts

huangyhg

"ductile failure" of anchor bolts
i am designing a base plate of a special concentrically based frame.  i understand that it is preferable to maintain a ductile failure mode.  does this just mean that the strength of the concrete embedment needs to be greater that the steel strength of the anchor bolts?  currently, i have 1 3/8" a36 anchor bolts with 30" embed.  the design tensile strength of 4 bolts is 257k.  the design breakout strength of the 4 bolt group is 279k.  the amplified seismic uplift is 176k.  so 279k is greater than 257k and the design is "ductile."  is this correct?  do i need to maintain a certain factor of safety for ductility? thanks.

no, you got it correct.  the steel will yield prior to concrete breakout.