Читать книгу Strength Of Beams, Floor And Roofs - Including Directions For Designing And Detailing Roof Trusses, With Criticism Of Various Forms Of Timber Construction - Frank E. Kidder - Страница 12

To determine the maximum safe distributed load for a cantilever beam of known dimensions.

Fig. 10.—Load Extending from the Support.

Fig. 11.—Beam Supported at the Center.

Let W = the amount of the load, in pounds, and L the distance in feet that the load extends from the support, as in Fig. 10. If the beam is supported at the center, as in Fig. 11, W should equal the load on each side of the support.

Rule 13.—To find the safe load W, multiply the breadth by the square of the depth and the product by the value for A, and divide by two times L (in feet).

To determine the SIZE OF BEAM required to support a known load, uniformly distributed on the beam, as in Figs. 10 and 11.*

Rule 14.—Assume the depth. To find the breadth, multiply twice the load by the distance L (in feet), and divide by the square of the depth multiplied by the value for A.