. American engineer and railroad journal . nsidered as having a uniform section, equivalent to the governing section and extending from pin to pin This assumption is accurate for side rods, but for main rods gives stresses at high speeds, possibly one per cent higher than those found by the accurate method. If A=;Governing area of rod, in square inches and L^Rod length, center to center of pins, in inches, then G=.2833 AL and Gr=.2833 ALr. For side rods the bending moment M=.I25FL. The formulae for bending moment (M) for main roils and side rods, at the assumed speeds, are noted in the followi
. American engineer and railroad journal . nsidered as having a uniform section, equivalent to the governing section and extending from pin to pin This assumption is accurate for side rods, but for main rods gives stresses at high speeds, possibly one per cent higher than those found by the accurate method. If A=;Governing area of rod, in square inches and L^Rod length, center to center of pins, in inches, then G=.2833 AL and Gr=.2833 ALr. For side rods the bending moment M=.I25FL. The formulae for bending moment (M) for main roils and side rods, at the assumed speeds, are noted in the following tabulati(m:Revolutions per minute 265 325 375 420 M for main rods. .036AL-r .ossALr .073ALr .ogiALr M for side .o-iALr .io6AL-r .i42AUr .177ALVFrom the above, the stress due to whipping action may be found by means of the well-known formula, M-^5j1/=Stress, to which the stress due to end strains, assumed as maxima, must be added. The sum of these stresses should not exceed one-sixth of the ultimate tensile strength of the CHECKING FORMULAE. All measurements are given in inches and pounds. A — .Area of section considered. a ~ Width of section considered. b = Depth of section considered. Cj ^ Max. compression unit stress for transverse bending. Ca=Max. compression unit stress for vertical bending. c^Cj — c = coefficients. d =r Cylinder diameter. L = Length of rod from centre to centre of pins. M =r Bending moment. P — Max. compression strain acting at end of rod. p ^ Max. boiler pressure. Q = Cylinder pressure =^ d- p. R ~ Radius of driving wheels. r =z Radius of crank. RG — Radius of gyration of section — axis horizontal. rg — Radius of gyration of section — axis vertical. S — Stress — and where used in formula must not exceed one-sixth of ultimate strength of the ~ .Amount of horizontal offset in rod. SM = Section modulus of section considered — axis = Section modulus of section considered — axis vertical,it-=
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectrailroadengineering
