What do structural engineers mean by "bolt tear out"?

[awa5114]

I have been assigned the task of checking bolt tear out for one bolt fastening a plate. Which limit state do structural engineers refer to when they say "bolt tear out"? Shear Rupture, Block Shear or another one? Thanks

 

[TehMightyEngineer]

All of them. Bolt tear out is failure of the connected part at the bolt hole locations. It's everything that's not failure of the bolts themselves or failure away from the bolt holes (gross yielding/fracture).

Professional and Structural Engineer (ME, NH)
American Concrete Industries

http://www.americanconcrete.com

 

[WillisV]

Bolt bearing and tearout are currently presented together in an inequality in the AISC Spec. Looking at the 14th Ed. Manual (2010 Spec.), see Eq. J3-6a or J3-6b as appropriate, the side of the inequality with lc is the bolt tearout limit state, and the side with the bolt diameter d is the bolt bearing limit state.

 

[rb1957]

tear-out is the failure of the plates being bolted together from in-plane loads, where the bolt literally rips it's way free of the plate.

another day in paradise, or is paradise one day closer ?

 

[BUGGAR]

"Block shear" is what the engineer says. "Bolt tear out" is what the Press reports.
"Shear rupture" is what goes into the tabloids.

 

[racookpe1978]

"Shear terror" followed soon thereafter by "sheets of tears" occurs underneath the beam after the bolt shears, after the beam shears, or the bolt tears.

 

[wannabeSE]

Buggar -
The commentary to section J3.10 of AISC 360-10 states "Material bearing strength may be limited either by bearing deformation of the hole or by tearout (a bolt-by-bolt block shear rupture) of the material upon which the bolt bears." Is AISC 360 a tabloid written by engineers and reported by the press?

 

[JasonMcKee71]

In other words, tear out failure is same to shear blocking failure. The design codes fully cover that thing and provide sufficient formulae to estimate the corresponding resistances.

Jason McKee
proud R&D Manager of
Cross Section Analysis & Design
Software for the structural design of cross sections
Moment Curvature Analysis
Interaction Diagrams
Reifnorcement Design etc.