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Stiffness and deflection calculations for a Bentley III Yoke, including a beam diagram.


Identifier  ExFiles\Box 127\1\  scan0369
Date  27th May 1938
  
-3-

STIFFNESS OF BENTLEY III YOKE.

[Diagram of a beam with the following labels: Clockwise moment M and downward force 1400 lbs at point O. {Mr Oldham} Upward force 1000 lbs at distance 'a"'. Upward curved arrow labeled 14500 lbs-ins near the center. Downward force 400 lbs at point B. Total length O to B is 10". A variable distance 'x"' is marked from O. {Mr Oldham} ]

(1) Deflexion of A below O due to bending.

Mx {John H Maddocks - Chief Proving Officer} = -14,500 + 1,000 (a - x) + 400 (10 - x)

EI d²y/dx² = 14,500 - 1,000 (a - x) - 400 (10 - x)

EI dy {F R Danby} /dx = 14,500x - 1,000 (ax - x²/2) - 400 (10x - x²/2) + α

EI y = 14,500x²/2 - 1,000 (ax²/2 - x³/6) - 400 {10x²/2 - x³/6} + αx + β

α = 0 because dy {F R Danby} /dx = 0 at O
β = 0 " y = 0 at O

EI yA = 7,250 a² - 333a³ - 2,000a² + 67a³
= 5,250 a² - 267a³

yA = 1/EI (5,250 a² - 267a³)
  
  
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).


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