Simplified consideration of down-aisle stability in pallet racking

The sway buckling loads predicted by the approximate equations given in European pallet racking codes are compared with those predicted by frame finite element analysis. It is found that the load capacities predicted by the approximate equations are accurate and conservative in comparison to the finite element predictions if the uprights are pin-ended and the spacing between all beam levels is constant. If the uprights have base rotational restraint, and/or the height of the first storey is less than that of the higher storeys then inaccuracy and non-conservatism can arise using the approximate equations, and the non-conservatism increases as the number of storeys increases. An attempt is made to improve the accuracy by modifying the approximate equations. The modified equations give, in general, more accurate predictions of sway buckling loads and in particular reduce the non-conservatism. The modifications also tend to ensure that for racks with properties outside the range examined in this paper the buckling loads predicted would err on the safe side.