354 BELL SYSTEM TECHNICAL JOURNAL 



the packaged article and gives methods for determining whether or not the 

 strength of the packaged article will be exceeded. The strength deter- 

 minations themselves are not dealt with here; but the information in Part III 

 is essential in interpreting and applying the data obtained in strength meas- 

 urements. In Part IV some consideration is given to the influence of dis- 

 tributed mass and elasticity. 



It cannot be emphasized too strongly that the determination of the mech- 

 anical properties of the packaged article, not dealt with in this paper, is an 

 essential preliminary to a rational design procedure for packaging. The 

 whole purpose in designing package cushioning is to limit the forces which 

 may act on the packaged item. If one does not know to what values to 

 limit the forces, a rational design procedure cannot be apphed. 



It is interesting to observe that the methods described here for analyzing 

 and designing package cushioning are directly applicable to the design of 

 shock mounts intended to protect equipment from the effects of a sudden 

 change in velocity. All of the principles, formulas and design curves given 

 here may be used in the shock mount problem with the simple substitution 

 of V-/2g for //, where h is the height of drop in the packaging problem, g is 

 the acceleration of gravity and V is the velocity change in the shock mount 

 problem. 



This paper is essentially a report on a study undertaken at the Bell Tele- 

 phone Laboratories, Inc., in the Electronic Apparatus Development 

 Department. The results have been applied to the packaging of- large 

 vacuum tubes and all of the examples used to illustrate the analysis and 

 design procedures in the paper are taken from vacuum tube applications. 



Miss H. A. Lefkowitz, Member of the Technical Staff, Bell Telephone 

 Laboratories, assisted in the mathematical studies. The oscillograms, used 

 as illustrations, were prepared under the supervision of Mr. F. W. Stubner, 

 Member of the Technical Staff, Bell Telephone Laboratories. Figure 

 3.8.2 was taken from a thesis submitted by Mr. C. Ulucay in partial fulfill- 

 ment of the requirements for the degree of Master of Science in the Depart- 

 ment of Civil Engineering at Columbia University. The calculations for 

 Figs. 3.5.1 to 3.5.6 and Fig. 3.2.2 for jSi > were performed on the Westing- 

 house Mechanical Transients Analyzer under the supervision of Dr. G. 

 D. McCann, Transmission Engineer, Westinghouse Electric and Manu- 

 facturing Company. 



Assumptions 



The procedures to be described for the analysis and design of package 

 cushioning are based on appUcations of a few simple laws of mechanics to 

 an idealized mechanical system representing the package and its contents. 



