. The strength of materials; a text-book for engineers and architects. Tnmetry Y Y, Fig. 81. Then this line y. Fig. 81. di^^des the area into two exactly similar halves so thatcorresponding to each element of area at p having a positive GEOMETRICAL PROPERTIES OF SECTIONS 167 moment about Y y we have an equal element at p having anequal negative moment about y y so that the total moment ofthe area about Y Y is zero, or Y Y passes through the centroid. If the figure has another axis of symmetry x x, the centroidalso lies on this line, or we have the rule that the centroid of afigure is at the in
. The strength of materials; a text-book for engineers and architects. Tnmetry Y Y, Fig. 81. Then this line y. Fig. 81. di^^des the area into two exactly similar halves so thatcorresponding to each element of area at p having a positive GEOMETRICAL PROPERTIES OF SECTIONS 167 moment about Y y we have an equal element at p having anequal negative moment about y y so that the total moment ofthe area about Y Y is zero, or Y Y passes through the centroid. If the figure has another axis of symmetry x x, the centroidalso lies on this line, or we have the rule that the centroid of afigure is at the intersection of two axes of symmetry. For the determination of the position of the centroid forvarious cases see p. 175-189. It should be noted that the centroid of an area is the sameas the centre of gravity of a template of the same shape as thearea. Second Moments or Moments of Inertia. — Therforce(/) ^product of a 4 ^^^^ (^) I by the square of its distance r from a[volume {v)j fforce ^ given point or axis is called the second moment of the - ^^^^about the given line or axis. [volumej Now, in consideri
Size: 1238px × 2018px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyorkdvannostran
