Page 23 - Shigley's Mechanical Engineering Design

bud29281_fm_i-xxii_1.qxd 12/24/09 3:38 PM Page xx epg Disk1:Desktop Folder:TEMPWORK:Don't-Delete Jobs:MHDQ196/Budynas:

xx Mechanical Engineering Design
J Mechanical equivalent of heat, polar second moment of area, geometry factor
j Unit vector in the y-direction
K Service factor, stress-concentration factor, stress-augmentation factor,
torque coefficient
k Marin endurance limit modifying factor, spring rate
k k variate, unit vector in the z-direction
L Length, life, fundamental dimension length
Life in hours
LN Lognormal distribution
l Length
M Fundamental dimension mass, moment
M Moment vector, moment variate
m Mass, slope, strain-strengthening exponent
N Normal force, number, rotational speed
N Normal distribution
n Load factor, rotational speed, safety factor
n d Design factor
P Force, pressure, diametral pitch
PDF Probability density function
p Pitch, pressure, probability
Q First moment of area, imaginary force, volume
q Distributed load, notch sensitivity
R Radius, reaction force, reliability, Rockwell hardness, stress ratio
R Vector reaction force
r Correlation coefficient, radius
r Distance vector
S Sommerfeld number, strength
S S variate
s Distance, sample standard deviation, stress
T Temperature, tolerance, torque, fundamental dimension time
T Torque vector, torque variate
t Distance, Student’s t-statistic, time, tolerance
U Strain energy
U Uniform distribution
u Strain energy per unit volume
V Linear velocity, shear force
v Linear velocity
W Cold-work factor, load, weight
W Weibull distribution
w Distance, gap, load intensity
w Vector distance
X Coordinate, truncated number
x Coordinate, true value of a number, Weibull parameter
x x variate
Y Coordinate
y Coordinate, deflection
y y variate
Z Coordinate, section modulus, viscosity
z Standard deviation of the unit normal distribution
z Variate of z