Investigation of the effects of looseness of bracing components in the cross-aisle direction on the ultimate load-carrying capacity of pallet rack frames

The shear stiffness of pallet rack uprights in the cross-aisle direction is determined experimentally by a load test involving repeated tensile or compressive loading of a cross-aisle frame without cycling through the origin. The effects of looseness are ignored. This paper describes the results of a series of tests involving full cyclic loading through the origin, not only to determine the stiffness of the frame but also the looseness inherent in the connection. Design recommendations are made to include the effects of looseness in cross-aisle sway analyses and to use cyclic testing to determine the shear stiffness of racking frames.A parametric study was conducted on a commercial frame which showed that if the design recommendations are adhered to that the influence of shear stiffness in the cross-aisle direction does not normally have a significant effect on frame capacity.