Mechanics Applied to Engineering
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1906 edition. Excerpt: ...fails. It will bend down slightly at the outer end, but that we may neglect for the present. The failure will be due to the outer part shearing or sliding off bodily from the built-in part of the cantilever, as shown in dotted lines. The shear on all vertical sections, such as ab or a'b', is of the same value, and equal to W. ln the case of the beam in Fig. 393, the middle part will shear or slide down relatively to I Fixed, the two ends, as shown in dotted----lines. The shear on all vertical + sections between b and c is of the same value, and equal to R, and T on all vertical sections between a and c is equal to R, . We have spoken above of positive and negative bending moments. We shall also find it convenient to speak of positive and negative shears. When the sheared part slides in a jclockwlse. X t contra-clockwise) direction relatively to the fixed part, we term it a positive (+) shear 1 (negative (--) shear j Shear Diagrams.--In order to show clearly the amount of shear at various sections of a beam, we frequently make use of shear diagrams. In cases in which the shear is partly positive and partly negative, we shall invariably place the positive part of the shear diagram above the base-line, and the negative part below the base-line. Attention to this point will save endless trouble. In Fig. 392, the shear is positive and constant at all vertical sections, and equal to W. This is very simply represented graphically by constructing a diagram immediately under the beam or cantilever of the same length, and whose depth is equal to W on some given scale, then the depth of this diagram at every point represents on the same scale the shear at that point. Usually the shear diagram will not be of uniform depth. The construction for various...
- Paperback | 148 pages
- 189 x 246 x 8mm | 277g
- 13 Sep 2013
- Illustrations, black and white