152_Mechanics SolutionInstructors_Sol.Manual-Mechanics_Materials_7e.book_Gere_light.1

# 152_Mechanics SolutionInstructors_Sol.Manual-Mechanics_Materials_7e.book_Gere_light.1

This preview shows page 1. Sign up to view the full content.

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Sec_2.4.qxd 146 9/25/08 11:38 AM Page 146 CHAPTER 2 Axially Loaded Members Solution 2.4-14 Bar supported by a collar FREE-BODY DIAGRAM OF BAR ABC AND COLLAR BD SOLVE SIMULTANEOUSLY EQS. (1) AND (3): PL3A1 PL1A3 RA RD L1A3 + L3A1 L1A3 + L3A1 CHANGES IN LENGTHS (Elongation is positive) RAL1 PL1L3 PL2 dBC dAB EA1 E(L1A3 + L3A1) EA2 ELONGATION OF BAR ABC AC AB AC SUBSTITUTE NUMERICAL VALUES: P 40 kN E L1 Fvert 0 RA P 0 (Eq. 1) COMPATIBILITY (distance AD does not change) AB(bar) BD(collar) 0 (Eq. 2) 125 mm A1 RD 225 mm L3 EQUILIBRIUM OF BAR ABC 250 mm L2 960 mm2 A2 300 mm2 A3 200 GPa 480 mm2 RESULTS: (Elongation is positive.) RA 0.02604 mm BC Substitute into Eq. (2): RDL3 RAL1 0 EA1 EA3 RD AB FORCE-DISPLACEMENT RELATIONS RAL1 RDL3 dBD dAB EA1 EA3 0.15000 mm AC 20 kN AB ; 0.176 mm AC (Eq. 3) Problem 2.4-15 A rigid bar AB of length L 66 in. is hinged to a support at A and supported by two vertical wires attached at points C and D (see figure). Both wires have the same cross-sectional area (A 0.0272 in.2) and are made of the same material (modulus E 30 106 psi). The wire at C has length h 18 in. and the wire at D has length twice that amount. The horizontal distances are c 20 in. and d 50 in. (a) Determine the tensile stresses C and D in the wires due to the load P 340 lb acting at end B of the bar. (b) Find the downward displacement B at end B of the bar. 2h h A C D B c d P L ...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online