________________________________________________________________________ PROBLEM (11.43) An ASTM A-47 cast-iron pipe of outer diameter d and wall thickness t is to serve as a pinned-end column of length L and is to support an eccentric load of P with a safety factor n s (Fig. P11.43). Calculate the largest allowable eccentricity e. Given: d = 10 in., t = ¾ in., L = 15 ft, P = 160 kips, n s = 2, E = 24 x 10 6 psi, σy = 33 ksi SOLUTION P = ns (160) = 2(160) = 320 kips , I= π A= π 4 (102 − 8.52 ) = 21.79 in.2 (104 − 8.54 ) = 234.6 in.4 64 From Example A.4: 1 1 r= D2 + d 2 = 102 + 8.52 = 3.28 in. 4 4 We have 320 P = = 14.68 ksi A 21.79 5e ec = = 0.4648e 2 (3.28) 2 r L 180 = = 54.88 r 3.28 Substitute these into Eq. (11.20b): ⎡ ⎛ 14.68 × 103 33 = 14.68 ⎢1 + 0.4648e sec ⎜ 27.44 ⎜ 24 ×106 ⎢⎣ ⎝ from which e = 2.09 in. ⎞⎤ ⎟⎥ ⎟⎥ ⎠⎦ Excerpts from this work may be reproduced by instructors for distribution on a not-for-profit basis for testing or instructional purposes only to students enrolled in courses for which the textbook has been adopted. Any other reproduction or translation of this work beyond that permitted by Sections 107 or 108 of the 1976 United States Copyright Act without the permission of the copyright owner is unlawful.