Cushion Design From Fragility Rating

GENERAL problems which arise in packaging design are treated, including a discussion of cushioning characteristics, fragility rating, and the energy concept of static and dynamic testing of cushion material.

A nomogram is presented which can be of use in designing cushioning installations.

The author suggests the following:

1. 1.
   For maximum vibration protection, the natural frequency of the cushioned package should be at least one-third of the lowest critical-component natural frequency in the equipment shipped.
2. 2.
   For necessary protection of equipment such as guided missiles, all-metal mounting systems of nonlinear design combined with a damping ratio of 20% should be employed.