. The Americana; a universal reference library, comprising the arts and sciences, literature, history, biography, geography, commerce, etc., of the world. Fig. i8. Fig. 20. Fig. 21. of the angles; their number, however, ought tobe so limited that the length of the rivets usedare not more than five times their the stress in the web plate is transmittedto the covers through the angles, the sectionalarea of the angles ought to be equal to or greaterthan that of the cover plates. In a girder, thebending moment requires cover plates of differ-ent lengths. This necessitates the notchi
. The Americana; a universal reference library, comprising the arts and sciences, literature, history, biography, geography, commerce, etc., of the world. Fig. i8. Fig. 20. Fig. 21. of the angles; their number, however, ought tobe so limited that the length of the rivets usedare not more than five times their the stress in the web plate is transmittedto the covers through the angles, the sectionalarea of the angles ought to be equal to or greaterthan that of the cover plates. In a girder, thebending moment requires cover plates of differ-ent lengths. This necessitates the notching ofthe cross-ties unequally. This is obviated byvarious modifications of the flange — by usinga narrow outer cover extending the whole lengthof the girder and placing filler plates under it,or by the use of two small angles, the cross-tiesbeing notched to fit the vertical legs of theangles. See Figs. i8, 19, 20, 21. Other methods are illustrated by Figs. 22 and. Fig. 22. Fig. 24. Fig. 23. 23, while Fig. 24 shows the section of a flangeat the end of a girder. The functions nf intermediate web stiffenersare in a rather undetermined condition, and the practice in their use varies considerably. Itmay be broadly stated, however, that the generalpractice is to use stiffeners 3^ x 3/2 x fg*angles for spans below 50 feet; 5x3^x^,angles for spans from 50 to 100 feet, and6 X 4 X y^ angles for spans over 100 feet. The size and weight of web plates are lim-ited by the processes of manufacture and avail-able equipment. Therefore, large girders re-quire several web splices. In their simplestform they consist of plates equal in length tothe clear distance between the flange angles,and are riveted to each of the two abutting webplates by two or more rows of rivets, with apair of stiffener angles attached. For spans less than 60 feet, splices in theflanges may usually be avoided, as angles andcover plates of sufficient length can be readilyobtained. In any ca
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectencyclo, bookyear1908
