Practical Steel Construction; Dealing with All Phases in the Construction of Our Modern Steel Buildings. [Appendix - Structural Steel.] (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1913 Excerpt: ...is being drawn has a net flange area of 21 sq. in., and making up this area there are four flange plates, each having an area of 4 sq. in., and two flange angles having a net area of 9 sq. in. It is now necessary to divide the line e d into such portions as will graphically represent the net flange area of the plates and of the flange angles; for instance, each plate will be in length equal to 4-21 of the length c d, and the two flange angles will equal 9-21 of this line. The most convenient way to lead out this line to the true proportions is to place the scale across the figure at any angle until, in this case, 21 divisions are contained between the two horizontal lines e f and a b; this scale is shown at p1?1, and the method is sufficiently clear from the figure. Through the points p, q, r, s, draw the horizontal lines as shown, and where these lines intersect the parabola, as at t, u v, draw upwards vertical lines as designated at v, w, u, y, and ty; the length of the several flange plates may then be readily determined by scaling the distances of y, x, and w respectively from the central line c d. This will give one-half the length of the flange plate, theoretically; one foot should be added to this length in order to allow for rivetting. In this case the theoretical lengths of the first, second, third, and fourth flange plates are found to be as designated in the figure. The entire theoretical length of the flange plate in each -ase being twice this distance, measured for the respective plates from the centre line c d, plus the 2 ft. added to each of the plates for rivetting. The diagram for determining the length of the flange plates, where the girder supports several concentrated loads, is similarly constructed as shown in E, Fig. 2-?, the metho..