907_Mechanics SolutionInstructors_Sol.Manual-Mechanics_Materials_7e.book_Gere_light.1

# 907_Mechanics SolutionInstructors_Sol.Manual-Mechanics_Materials_7e.book_Gere_light.1

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SECTION 11.9 Design Formulas for Columns 901 Solution 11.9-17 Pipe column Pinned ends . Seltect various values of diameter d until we obtain . If , Use Eqs. (11-79) and (11-81). If , Use Eqs. (11-80) and (11-82). L Ú L c L L c P allow ± P a L r b c ± A 2 p 2 E s Y ± 126.1 L c ± (126.1) r r ± A I A ± 0.33634 d I ± p 64 [ d 4 ² ( d ² 2 t ) 4 ] ± 0.016881 d 4 A ± p 4 [ d 2 ² ( d ² 2 t ) 2 ] ± 0.14923 d 2 E ± 29,000 ksi s Y ± 36 ksi d ± outside diameter t ± d /20 L ± 20 ft ± 240 in. P ± 25 k ( K ± 1) For P ± 25 k, d ± 4.89 in. ; d (in.) 4.80 4.90 5.00 A (in. 2 ) 3.438 3.583 3.731 I (in. 4 ) 8.961 9.732 10.551 r (in.) 1.614 1.648 1.682 L c (in.) 204 208 212 L/r 148.7 145.6 142.7 n 2 (Eq. 11-80) 23/12 23/12 23/12 (Eq. 11-82) s allow / s Y 0.1876 0.1957 0.2037 s allow (ksi) 6.754 7.044 7.333 P allow ± A s allow 23.2 k 25.2 k 27.4 k Problem 11.9-18 Find the required outside diameter d for a steel pipe column (see figure) of length L ± 3.5 m that is pinned at both ends and must support an axial load P ± 130 kN. Assume that the wall thickness t is equal to d/20. (Use E ± 200 GPa and .) s Y ± 275 MPa Solution 11.9-18 Pipe column Pinned ends . Select various values of diameter
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Unformatted text preview: d until we obtain . If , Use Eqs. (11-79) and (11-81). If , Use Eqs. (11-80) and (11-82). L L c L L c P allow P a L r b c A 2 p 2 E s Y 119.8 L c (119.8) r 0.33634 d r A I A I p 64 [ d 4 ( d 2 t ) 4 ] 0.016881 d 4 A p 4 [ d 2 ( d 2 t ) 2 ] 0.14923 d 2 E 200 GPa s Y 275 MPa d outside diameter t d /20 L 3.5 m P 130 kN ( K 1) d (mm) 98 99 100 A (mm 2 ) 1433 1463 1492 I (mm 4 ) 1557 * 10 3 1622 * 10 3 1688 * 10 3 r (mm) 32.96 33.30 33.64 L c (mm) 3950 3989 4030 L/r 106.2 105.1 104.0 n 1 (Eq. 11-79) 1.912 1.911 1.910 (Eq. 11-81) s allow / s Y 0.3175 0.3219 0.3263 s allow (MPa) 87.32 88.53 89.73 P allow A s allow 125.1 kN 129.5 kN 133.9 kN For P 130 kN, d 99 mm ; 11Ch11.qxd 9/27/08 2:27 PM Page 901...
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## This note was uploaded on 12/22/2011 for the course MEEG 310 taught by Professor Staff during the Fall '11 term at University of Delaware.

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