DYNAMICS OF PACKAGE CUSHIONING 461 



:V2 Acceleration of wo- 



•Tmax Maximum value of x. 



ix2)n In Section 1.15, the displacement associated with the n^^' point. 



Xst The value x would have if the acceleration reached its maximum value 

 in a very long time. 



(A.T2)n In Section 1.15, equals (x2)„ — (.T2)„_i. 



y X2-Xi. 



z xn/l (tension spring package). 



«) y> ^i s") '7 Phase angles. 



/3i Fraction of critical damping of an element of the packaged article. 



/32 Fraction of critical damping of package cushioning. 



7„ Phase angle of n"> term of series (equation (4.3.22)). 



e Strain at attached end of element under transient conditions. 



eo Strain at attached end of element under non-transient conditions. 



em Maximum strain at attached end of element under transient conditions. 



6 Angle between the displacement direction and the acceleration di- 

 rection. 



IT 3.14159---. 



p Density (mass per unit of volume) 



TO Pulse duration of a half-sine-wave acceleration. 



T2 Pulse duration associated with non-linear cushioning. 



tb Duration of bottoming of cushioning with bi-linear elasticity. 



Tp Time required to reach peak vs,lue of a triangular acceleration pulse. 



w Radian frequency defined in equation (2.4.6). 



wi Radian frequency' of vibration of an element of the packaged article. 



wi' Radian frequency of vibration of damped element of packaged article. 



0)2 Radian frequency of vibration of the packaged article on its cushioning. 



W2' Radian frequency of vibration of the packaged article on damped 

 cushioning. 



ub A frecjuency defmed in equation (2.10.10). 



Wc A frequency defined in equation (2.8.8). 



w„ Radian frequency of nth mode. 



