. Graphical and mechanical computation . Fig. 45^. The scales are x = mid2, y = m2D2, z = m3 (/ - p), I = w4 (/ + p), and the following table exhibits the choice of moduli: Scale Limits Modulus Equation Length d 2 to 16 Wi = x = = d2 D 2 to 20 w2 = y = = D2 8 f-p 0 to 10,000 m3 = z = = (/ - P) 7-5 f + P 0 to 20,000 m4 w2w3= = 0 .0005 t = = (/ + p) 10 mx The (d, D) and (/ — p, f + p) index lines must be perpendicular. Thechart is given in Fig. 48, and the index lines drawn show that when/ =9000 pounds per sq. in., p = 1000 pounds per sq. in., and d
. Graphical and mechanical computation . Fig. 45^. The scales are x = mid2, y = m2D2, z = m3 (/ - p), I = w4 (/ + p), and the following table exhibits the choice of moduli: Scale Limits Modulus Equation Length d 2 to 16 Wi = x = = d2 D 2 to 20 w2 = y = = D2 8 f-p 0 to 10,000 m3 = z = = (/ - P) 7-5 f + P 0 to 20,000 m4 w2w3= = 0 .0005 t = = (/ + p) 10 mx The (d, D) and (/ — p, f + p) index lines must be perpendicular. Thechart is given in Fig. 48, and the index lines drawn show that when/ =9000 pounds per sq. in., p = 1000 pounds per sq. in., and d = 9 in., thenD = in. (VH) EQUATION OF FORM fx(u) -/«(») =/,(w) -Mq) OR f^u): Uv) = f3(w): /4(q). PARALLEL OR PERPENDICULAR INDEX LINES 49. Chart for equation (VII). — The second form of equation (VII)can be immediately transformed into the first form by taking logarithmsof both members of the equation. This second form of equation (VII)is the same as equation (VI), but we shall here use logarithmic scales incharting it. r-Si. ga Art. 49 CHART FOR EQUATION (VII) 93 Consider a pair of parallel axes AX and BY, k\ inches apart, and an-other pair of parallel axes CZ and DT, k2 inches apart, parallel to the firstpair; AB and CD are also parallel. (Fig. 49a.) Draw two parallelindex lines, one intersecting AX and BY and the other intersecting CZ
Size: 1173px × 2132px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubj, booksubjectengineering
