Another important element in the evaluation of drop and shock is the shape of the parcel and drop side. A box has 6 sides but a drop seldom hit parallel to such a side. The normal situation is a drop will hit first a corner (>90%) or maybe an edge (~2-5%) and only in worst case parallel to the side. But these three events give very different shock history.
The figure illustrates three different shock events as a result of a free drop from the same height. The first shock event is a result of a corner is hitting the ground first – next an edge drop and last a side drop. The result will be three different tops or three small independent shocks. I case of an edge is hitting ground first the result is either a two top event or two independent shocks. Only in the seldom cases of a parallel side shock when the box is hitting the ground parallel to the ground the result will be one big shock. The forces in the shock are highest at a side event but the energy is exactly the same illustrated by the area under the curves are the same. The shocks on the diagrams last between 2-20 msec.
For specification of drop direction please use ISO2206.
Side drop - specify drop 3 for a drop on the bottom (figure 1).
Edge drop - specify drop 2-5 for a drop on the edge near to you (figure 1).
Corner drop - specify drop 1-2-5 for a drop on the corner near to you (figure 1).