Eccentrically loaded connections

P(3) An eccentrically loaded connection is a connection where the line of action of the applied load does not pass through the centroid of the fastener group. The connection is subjected to a twisting moment in addition to a concentric force. Bracket-type connections, web splices in beams, and standard beam connections are common examples of eccentrically loaded connections (see Figure 5.10). 

Depending on the local arrangement of the connections, the fasteners may act in single or double shear, the former giving rise to out-of-plane bending for both concentrically and eccentrically loaded connections. 

For purposes of this specification, stresses in the individual members of a latticed or trussed structure resulting from elastic deformation and rigidity of joints are defined as secondary stresses. These secondary stresses may be taken to be the difference between stresses from an analysis assuming fully rigid joints, with loads applied only at the joints, and stresses from a similar analysis with pinned joints. Stresses arising from eccentric joint connections, or from transverse loading of members between joints, or from applied moments, must be considered primary stresses. 

It is assumed that the rotation of the connection takes place about c.g. The eccentric load is resolved into a concentric load, acting through c.g. (see Figure 5.11) and a torsional moment, M=Fe (Figure 5.12). 

---