AISC 360-05 H3.3 'constrained local yielding'

[wishnias]

Putting together an analysis of an existing bent plate connecting element, ~200in^2 total. FEA is showing an area of ~3in^2 exceeding material yield strength, peaking at about 160%. (A36 steel hitting nearly 60ksi)

Does anyone know how to quantify the allowance in the code, as written at the end of section H3.3: "Some constrained local yielding is permitted adjacent to areas that remain elastic" There is nothing in the commentary.

 

[ash060]

Something is not right in your analysis I think. Are you modeling the material as elastic? At 60 ksi the steel should rupture. A36 Fu = 58 ksi

Check your model and see what the material properties are. I would recommend elastic-plastic stress-strain

 

[wishnias]

There is nothing wrong with my analysis, I am aware that I am near material rupture.

My question was on the interpretation/quantification of the statement in the code.

 

[ishvaaag]

I would say for a start that any overstress coming from accepted details from standard calculations should constitute a frame of reference of such overstress allowance (otherwise the standard calculations should be removed from the code, for many of them give overstress locally).

I think also logic can be of help. If you have a nut head and washer falling entirely on an entirely plastified area at limit states, just over Fy (how less over Fu) I wouldn't go with it, except that some explicit code procedure assures me the design is correct. The reason for this is that to do so would mean to rely on overstrength (and concomitant high deformation) to stand the limit forces, and one wouldn't want to do so except maybe for some earthquake, impact or blast scenario where some standing plastification after application of the loads may be surmised acceptable.