机器设计-综合方法p0454.pdf

MACHINEDESIGN-AnIntegratedApproach,4thEd.4-54-1

PROBLEM4-54

Statement:Threeround,1.25-barsaremadeofSAE1030hot-rolledsteelbutareofdifferentlengths,

5in,30in,and60in,respectively.Theyareloadedaxiallyincompression.Comparetheload

supportingcapabilityofthethreebarsifsareassumedtobe:

(a)Pinned-pinned.

(b)Fixed-pinned.

(c)Fixed-fixed.

(d)Fixed-free.

Given:Outsidediameterd1.25in

LengthsL5inL30inL60ini123

123

MaterialSAE1030SteelYieldstrengthS38ksiy

6

ModulusofelasticityE3010psi

Solution:SeeMathcadfileP0454.

1.Calculatetheslendernessratiothatdividestheunitloadvs.slendernessratiographintoJohnsonandEuler

regions.

2E

SπS124.8

rDrD