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).
Technical analysis comparing the frame stiffness of a 'Rippletto' frame with a Bentley V frame, including calculations and formulas.
| Identifier | ExFiles\Box 100\3\ scan0090 | |
| Date | 30th October 1939 | |
| Appendix Sheet 4. Ev.{Ivan Evernden - coachwork}1/JH.30.10.39. Rippletto Frame Stiffness. Equivalent lengths of front arms measuring from the front wheels to the node. B.V. = 40.000 ins. Rippletto = 32.500 ins. (with Ripplet frame). Rippletto = 26.000 ins. (with shortened frame). If h = frequency. W = equivalent single load. w = weight of frame per unit length. l = length of arm. h = (1 / 2π) * (3EIg / (l³(W + 33wl/140))) It can be shewn that w, is so small that it may be taken as,zero, then - h = (1 / 2π) * (3EIg / l³W) Likewise it has been computed that the ratio of concentrated equivalent weights may be - B.V. = 10 units. Rippletto = 8 units. The I of the sections are as follows - Bentley V = .104 a Rippletto = .064a (with Ripplet frame) Rippletto = .064 x a x (5² / 6.25) = .041a (with short frame) Comparing B.V. with Rippletto - with Ripplet frame. hBV / hR = ( (.104 x 32.5³ x 8) / (.064 x 40³ x 10) )^(1/2) = .836. | ||