Notes and examples in mechanics; with an appendix on the graphical statics of mechanism; (1897)
Church, Irving P. (Irving Porter), 1851-1931 · New York, J. Wiley & Sons · leaf 50
Fig. 49. E=PGOsec (X— P -^ sin a. (The summation of horizontal andvertical components put equal to zero would give the same result.)^is tension ; E, compression. Next take the free body in Fig. 50, involving the known forceP and the i.nknown stresses P, 7, and Z,assuming for them the characters… … Ph — Pa = 0 ; whence P =and is tension. From 2 (vert, comps.), P = Z cos /?, or Z = -f P P a and cos /i is therefore compression as assumed ; while, from ^(hor. comps.)^0, I— P -E sin /? rn.0 ; i.e., /= + P(tan /? + cot a\ andis compression. To find the stresses in A, P, and G we use the free body…
