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From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Mathematical calculations for deflection, comparing Packard and Bentley III models, and analyzing the B.III Yoke.

Identifier  ExFiles\Box 127\1\  scan0371
Date  27th May 1938
  
-5-

Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}6/WH.27.5.38.

EIyB" = -133 (10 - a)³
= -133 (1000 - 300a + 30a² - a³)
= -133,000 + 40,000a - 4,000a² + 133a³

yB = 1/E.I. (-133,000 + 40,000a - 4,000a² + 133a³)

Total Deflexion =
1/E.I. (-133,000 + 145,000a - 12,250a² + 167a³)

Comparison of Packard and Bentley III.

Packard. If a = 3.62, numerator = 239,500
B.III. If a = 7.15, " = 338,000

Deflexion B.III/Packard = 141%

Actual Deflexion of B.III Yoke.

I = (π x D⁴) / 64
D varies between 1.25 and 1.50
Take D = 1.35

I = (π x 3.32) / 64 = .163

E = 30 x 10⁶
a = 7.15
Total yB = (-133,000 + 1,035,000 - 625,000 + 61,000) / (.163 x 30 x 10⁶)

= 338,000 / (4.9 x 10⁶) = .069"

Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale}
  
  


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