207_Mechanics SolutionInstructors_Sol.Manual-Mechanics_Materials_7e.book_Gere_light.1

207_Mechanics SolutionInstructors_Sol.Manual-Mechanics_Materials_7e.book_Gere_light.1

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

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Sec_2.7.qxd 9/25/08 11:42 AM Page 201 SECTION 2.7 Strain Energy 201 Solution 2.7-4 Bar with two loads (c) FORCES P AND Q ACT SIMULTANEOUSLY Segment BC: UBC (a) FORCE P ACTS ALONE (Q U1 P2L 2EA (P + Q)2(L/2) 2EA ; (b) FORCE Q ACTS ALONE (P 2 U2 Segment AB: UAB 0) P2(L/2) 2EA Q (L/2) 2EA PQL Q 2L P2L + + 4EA 2EA 4EA 0) 2 QL 4EA P2L 4EA ; U3 UBC + UAB PQL Q2L P2L + + 2EA 2EA 4EA ; (Note that U3 is not equal to U1 U2. In this case, U3 U1 U2. However, if Q is reversed in direction, U3 U1 U2. Thus, U3 may be larger or smaller than U1 U2.) Problem 2.7-5 Determine the strain energy per unit volume (units of psi) and the strain energy per unit weight (units of in.) that can be stored in each of the materials listed in the accompanying table, assuming that the material is stressed to the proportional limit. DATA FOR PROBLEM 2.7-5 Material Weight density (lb/in.3) Modulus of elasticity (ksi) Proportional limit (psi) Mild steel Tool steel Aluminum Rubber (soft) 0.284 0.284 0.0984 0.0405 30,000 30,000 10,500 0.300 36,000 75,000 60,000 300 Solution 2.7-5 Strain-energy density STRAIN ENERGY PER UNIT VOLUME DATA: Material Weight density (lb/in.3) Modulus of elasticity (ksi) Proportional limit (psi) Mild steel Tool steel Aluminum Rubber (soft) 0.284 0.284 0.0984 0.0405 30,000 30,000 10,500 0.300 36,000 75,000 60,000 300 P2L 2EA u U V Volume V s2 PL 2E AL Stress s U P A ...
View Full Document

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.

Ask a homework question - tutors are online