lower frequencies were analyzed similarly. The second harmonic forces resulting from the 

 1/4-inch oscillations were to small to be analyzed. As a result only 19 tests spots were 

 obtained. 



It was found when the widely scattered force data was divided by z^ (o^/2 that the re- 

 sulting damping coefficient B was scattered but remained within an interval of 0.06 to 0.16 

 lb-sec ^/in.-^, as shown in Figure 14. The accuracy of the data was too poor to define a 

 frequency, amplitude, or speed dependence. In Figure 15 the number of test points in an in- 

 terval is shown in a bar graph. We are compelled at this stage, to assume a single "best" 

 value of 0.11 + 0.05 for all speeds, frequencies, and amplitudes. 



0.20 



c- 0. 1 5 



I 

 u 



S 0.10 

 I. 0.05 

 



CQ 





o 









■ 





■ — j- 















D 



O 



( 



> 



A 



• 





'd 



Knots 

 |"Ampl. 

 "2 AmpI. 





 



• 



1 



D " 



■ 



2 



k 







9 



i 





k 



o 

 D 





40, 



• — 































12 16 



u) in rod/sec 



20 



24 



28 



Figure 14 - The Nonlinear Damping Coefficient B 





 |8 



c 







c 



l 























































X) 



i 2 



z 

















0.08 0.16 0,32 



Value of B, in lb — sec^/ in? 



Figure 15 - S, The Number of Points 

 in an Interval 



18 



