Murthy 



+ (6 3 , 8 Z P , 8Q 2 <x 8 2 a,a Z ) (1-1) 



2 2 2 



It may be as well to point out that the terms of 0( 8 13,88 6 a ] 



are slightly in deficit due to the forcible linearization implied in 

 writing 



x - x* = x + h_ + (0 2 ) 



/ 2, 

 where the 0(0) terms cannot be explicitly written down. 



We have written above 



r — x + h a 



klm — klm G p klm 



for the coupled displacement parameter and 



klm = 1 , klm 2 , klm 

 x 1 x' 



for the coupled stiffness function. 



It will be seen that the pitch and heave stiffness functions 

 enter only in the higher order terms. Also, if the cushion is truly 

 uniform in the longitudinal direction such that 



p = , p =0 



o o 



X XX 



the variation of pressure distribution due to the oscillations is of 

 a very high order. 



172 



