Tailing lug analysis is included in the basering analysis for a single or dual type design, as shown below. The design is based on a lift position where no bending occurs on the tailing lug. The location of the center of the pinhole is radial at the edge of the outer most of the top ring or the basering, whichever is larger. The tailing lug material is assumed to be the same material as the gusset or basering. The main considerations for the design are section modulus, shear and bearing stress at the pin hole, and weld strength.
A lug, also known as a lifting lug or a padeye, is essentially a plate with a hole in it where the hole is sized to fit a clevis pin. Lugs are used in combination with clevis pins to transmit load between different mechanical components. Common applications where lugs are used include:
*strongbacks with padeyes, lifted with shackles and other rigging
*connections between actuators and other structure (i.e. trunnion joint, clevis joint)
This method is based on first principles (as well as on the simplified method outlined in Bruhn) and involves making simplifying assumptions about the nature of the failure. While it is relatively easy to perform, it only gives an approximate determination of the adequacy of the lug and should not be employed for critical structure.
In the simplified analysis, the following failure modes are considered:
*Tension failure across the net section
*Shear failure along two planes
A factor of safety is calculated for each of the failure modes, and as long as each factor of safety is acceptable then the lug can be considered to pass.