Page 233 - Materials Science and Engineering An Introduction

Summary • 205

Equation Summary

Equation Page
Number Equation Solving For Number
F
6.1 s = Engineering stress 172
A 0
6.2 P = l i - l 0 = l Engineering strain 172
l 0 l 0
6.5 s = EP Modulus of elasticity (Hooke’s law) 174

P x P y
6.8 v = - = - Poisson’s ratio 177
P z P z
l f - l 0
6.11 %EL = a b * 100 Ductility, percent elongation 184
l 0
A 0 - A f
6.12 %RA = a b * 100 Ductility, percent reduction in area 184
A 0
F
6.15 s T = True stress 187
A i
l i
6.16 P T = ln True strain 188
l 0
n
6.19 s T = KP T True stress and true strain (plastic 188
region to point of necking)
6.20a TS(MPa) = 3.45 * HB
Tensile strength from Brinell hardness 196
6.20b TS(psi) = 500 * HB
s y
6.24 s w = Safe (working) stress 200
N

List of Symbols

Symbol Meaning
Specimen cross-sectional area prior load application
A 0
A f Specimen cross-sectional area at the point of fracture
A i Instantaneous specimen cross-sectional area during load application
E Modulus of elasticity (tension and compression)
F Applied force
HB Brinell hardness
K Material constant
l 0 Specimen length prior to load application
l f Specimen fracture length
l i Instantaneous specimen length during load application
N Factor of safety
n Strain-hardening exponent
(continued)