________________________________________________________________________ PROBLEM (11.34) The jib crane of Fig. P11.34a is constructed of a 35-mm-diameter rod BC and a steel tube AB. The approximate stress-strain curve for both members is shown in P11.34b. Determine the value of W at which failure occurs. Given: The steel tube has the following properties: A = 400 mm2 , I = 8x10 3 mm 4 , E = 200 GPa. SOLUTION FBC = 2W C FAB = W Rod d=35 m 1 Rod BC 1 45o 2.5 m A B W π 2W = 5 × 106 ( × 0.0352 ) = 4,811 4 or W = 3.4 kN Bar AB Py = 8 × 106 (400 ×10−6 ) = 3.2 kN W = Pcr = π 2 (200 ×109 )(8 × 10−9 ) (2.5) 2 = 2.53 kN and 2530 = 6.325 MPa < 8 MPa 400 ×10−6 Conclusion: bar AB fails as a column, and Wall = 2.53 kN σ cr = 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.