. Theory of structures and strength of materials. Fig. 99 is the stress-diagram due to Jiorizontal componentof wind-pressure, rollers being placed under B and the end Cbeing fixed. po = downward reaction at B ^ pjd sin^ a4 cos a 0 q = horizontal force of wmd at B = BF\ qm =? inn=? horizontal force of wind at/^or//^: -^ BH. Total resultant stresses in the members BF, FH, HA, DF,DH, DB, DA, DE are represented by qr — qr, ms — ms,nt — 7it, sr — sr, st — st, pr — pr, W — tv\ pv — pv,respectively. Note.—The stress diagrams for trusses with both of the lowerends of the principal rafters fixed, are d
. Theory of structures and strength of materials. Fig. 99 is the stress-diagram due to Jiorizontal componentof wind-pressure, rollers being placed under B and the end Cbeing fixed. po = downward reaction at B ^ pjd sin^ a4 cos a 0 q = horizontal force of wmd at B = BF\ qm =? inn=? horizontal force of wind at/^or//^: -^ BH. Total resultant stresses in the members BF, FH, HA, DF,DH, DB, DA, DE are represented by qr — qr, ms — ms,nt — 7it, sr — sr, st — st, pr — pr, W — tv\ pv — pv,respectively. Note.—The stress diagrams for trusses with both of the lowerends of the principal rafters fixed, are drawn in precisely thesame manner as described in the preceding examples. 52 THEORY OF STRUCTURES. Thus, in Fig. loo, S^S^S^S^S^S^ is the reciprocal of A, S^S^lepresenting the portion of the horizontal wind-pressure borne. Fig. ioo. at A. Again, HS^^H is the reciprocal of B, HS^ represent-ing the portion of the horizontal wind-pressure borne at ^ = HS^ -{- S^S^ = total horizontal wind-pressure, S^S^ repre-senting the vertical reaction at B, and HS^ that at C. 25. Bridge-trusses.—A bridge-truss proper consists ofan upper chord (or flange), a lower chord (or flange), and an in-termediate portion, called the web, connecting the two depth is made as small as possible consistent with economy,strength, and stiffness. Its purpose is to carry a distributedload, which, as in the case of roof-trusses, is assumed to beconcentrated at the joints, or panel-points, of the upper andlower chord. Trussed beams are also employed for the sameobject, and examples of simple frames of this class have alreadybeen given. The following are bridge-trusses of a more complex char-acter. Ex. I. The beam ^C(Fig. loi) is supported at three pointsby the vertical struts DF, AK, EG, which are tied at the feetby the r
Size: 2012px × 1242px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublishernewyo, bookyear1896
