DYNAMICS OF PACKAGE CUSHIONING 



411 



the fact that the load-displacement curve for tangent elasticity rises more 

 rapidly than that for cubic elasticity; that is, the bottoming is harder. 



4.5 



4.0 



3.5 



3.0 



2.5 



2.0 



1.5 



10 



1.5 



CJot 



20 



2.5 



3.0 



Fig. 2.9.2 — Acceleration-time curves for cushioning with tangent elasticity. 



The curves of Fig. 2.9.2 were obtained by numerical integration of equa- 

 tion (2.9.2), to obtain X2 as a function of /, following which these values 

 were substituted in the equation 



W2 X2 -\ tan — - =0 



TT zao 



to obtain .vo . It may be observed that the maximum values of the curves 

 are the values dictated by equation (1.9.4). 



