Environmental Engineering Reference
In-Depth Information
Nomenclature
A
Section area of elements
b
max,k
The largest length of the signal curve of every time series as the interval
time is k
b
min,k
The length of the signal curve which pass through no damaged region as
the interval time is k
C
System damping matrix
E
Elastic modulus, the residual error
FD
max
The largest value of estimated FD of the curve of each time series
J
FD-based damage acuteness index
K
System stiffness matrix
K
s
The structural stiffness
K
d
The additional stiffness
K
0
Is the normal modal stiffness matrix
K
1
(a)
The stiffness matrix of the geometric nonlinearities
L
The length of time series of PZT signal
M
System mass matrix
n
The degrees of freedom of the structure, the refractive index of the fiber
core
NI
The damage index based on PCA method
NI
The mean value of NI
t
Time
T
The loading matrix
u
0
The displacement in x direction
v
The external force
V
a
The velocity of the acoustic wave
m
B
The Brillouin frequency shift
v
0
The displacement in y direction
X
The scores matrix
X
The reconstructed data
Y
The compressed data
Z
The displacements of the degrees of freedom of the structure
Z
The velocities of the degrees of freedom of the structure
::
The accelerations of the degrees of freedom of the structure
Z
U
The potential energy of strain
a
The modal coordinate, the first Rayleigh damping coefficients
b
The second Rayleigh damping coefficients
e
The normal strain
k
The eigenvalues, the vacuum wavelength of the pump light
r
Standard deviation
x
The angular frequency
[]
The Gauss' notation
