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BELL SYSTEM TECHNICAL JOURNAL 



Notice that the amplification factor is Aq rather than Am. That is, 

 the reference acceleration is Go rather than Gm . This is necessary because 

 Gm is infinite in the present instance. Hence Fig. 3.7.2 cannot be com- 

 pared directly with Figs. 3.2.2 and 3.6.2. However, it is interesting to 

 observe that, for on/wt < 0.5, (low frequency elements) abrupt bottoming 

 has no harmful effect. For high-frequency elements, the severity of bottom- 

 ing is very great even when very nearly all of the required space (do) is 

 available. For example, if 90% of the required space is available (ds/do = 

 0.9) and the frequency of the element is ten times the package frequency. 



0123456789 10 



(Jo 

 Fig. 3.7.2 — Amplification factors for abrupt bottoming. See equations (3.7.1), (3.7.3) 



and (3.7.5). 



the severity of the shock is almost ten times as great as it would be if the 

 additional 10% of space were available. 



3.8 General Influence of Shape of Acceleration-Time Curve 

 ON Amplification Factor 



When amplification factor curves are not available for a special shape of 

 acceleration-time curve, an approximate value oi Am may be obtained by 

 interpolation between or extrapolation from the curves of the preceding 

 sections. The shape of the acceleration-time curve and its duration (72) 

 or frequency (0)2) should be found, first, by the methods described in Part II. 

 The shape found should then be compared with the standard shapes shown 

 in Part II, for which amplification factors are given in Part HI. 



The amplification factor found in this way will generally be within 25% 



