Single VS Double Shear Joints

When joining components fastened shear joints is a very common method in aerospace structures.  This method uses mechanical fasteners to join two or more components.  Two common types of this are single and double shear joints.

The following graphic is an idealized representation of a double row of fasteners in a single shear joint.

This differs from a double shear joint, which is shown below:

Several things need to be considered when determining the capability of a shear joint:

·       The shear capability of the fastener (and if there is tension the tension / combined capability)

·       Bearing strength of the material

·       Other edge distance concerns (shear tear out or net tension failure modes if applicable)

Calculating a Margin of Safety for the joint is a matter of determining the minimum joint "allowable" or capability and applying the M.S. equation with the applied load (p in this case).

\begin{align} M.S. & = \frac{ Allowable Load }{ Actual Load }-1\\ \end{align}