7.2.6 Main Takeaways on Failure of Mechanically Fastened Joints
Course subject(s)
Module 7. Joining of Structures and Manufacturing
Failure modes
Failure in mechanically fastened joints is a complex competition between different possible failure modes. We examined the major failure modes illustrated below and looked at which design variables are dominant in each failure mode.

Accompanying Failure Load Formulas
Net Section Failure: ๐น๐ ๐๐=๐ก(๐โ๐โ ๐)โ ๐๐ก๐ข, with n the number of fasteners along net section, d the diameter of the fastener, and t the plate thickness of the section.
Bearing Failure: ๐น๐๐=๐โ ๐กโ ๐๐๐, with d the diameter of the bolt and t the thickness of the sheet
Shear Out Failure: ๐น๐๐๐=2โ ๐โ ๐กโ ๐๐ ๐ข, with b the distance to the edge and t the thickness of the sheet.
Fastener Shear Failure:

,with d the diameter of the bolt and n the number of shear plains (n = 1 for 2 plates, n = 2 for 3 plates etc.)

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