when is a shakedown analysis required

huangyhg

when is a shakedown analysis required?
when is a shakedown analysis required? i.e. when do we need to analyze a structure to its ultimate failure mechanism?  
i hear shakedown analysis mentioned fairly frequently, but it has never been explained to me when this is actually required.  my work is primarily on commercial buildings in a non-seimic zone and i have never heard of such refined analysis used.  
are there some industrial applications where it is necessary?  or it is needed for some seismic applications?  i am curious to hear from anyone with experience in performing limit analysis.  thanks.
ultimate failure analysis can be done on anything you want...it just isn't usually done on buildings or static structures.  manufactured products, fracture critical structures, and other fatigue-oriented structures can benefit from such analyses.
shakedown can/should be used for plastic design whenever there is a possiblilty of load reversal.  lateral loads from wind and 'rigid' frames, for example.  i have a pretty decent power point discription of what it is... i'll try to dig it up later.
dik
dik,
i'd be happy to view your powerpoint if you will post it.