doc OpenSeismoMatlab
Documentation of the OpenSeismoMatlab function.
helpFun('OpenSeismoMatlab')
Seismic parameters and processing of an acceleration time history
Syntax
PARAM=OpenSeismoMatlab(DT,XGTT,SW,__)
PARAM=OpenSeismoMatlab(DT,XGTT,'PGA')
PARAM=OpenSeismoMatlab(DT,XGTT,'EPGA')
PARAM=OpenSeismoMatlab(DT,XGTT,'PGV')
PARAM=OpenSeismoMatlab(DT,XGTT,'PGD')
PARAM=OpenSeismoMatlab(DT,XGTT,'ARIAS')
PARAM=OpenSeismoMatlab(DT,XGTT,'SIH1952')
PARAM=OpenSeismoMatlab(DT,XGTT,'SINH1984')
PARAM=OpenSeismoMatlab(DT,XGTT,'TIMEHIST',BASELINESW)
PARAM=OpenSeismoMatlab(DT,XGTT,'SINCRESAMPLE',DTI)
PARAM=OpenSeismoMatlab(DT,XGT,'PULSEDECOMP',WNAME,TPMIN,TPMAX,...
NSCALES)
PARAM=OpenSeismoMatlab(DT,XGTT,'ELRS',T,KSI,ALGID,RINF,DTTOL)
PARAM=OpenSeismoMatlab(DT,XGTT,'RPSRS',CF,ALGID,RINF,MAXTOL,JMAX,DAK)
PARAM=OpenSeismoMatlab(DT,XGTT,'CDRS',T,KSI,MU,PYSF,DTTOL,ALGID,...
RINF,MAXTOL,JMAX,DAK)
PARAM=OpenSeismoMatlab(DT,XGTT,'CSRS',T,KSI,FYR,PYSF,DTTOL,ALGID,...
RINF,MAXTOL,JMAX,DAK)
PARAM=OpenSeismoMatlab(DT,XGTT,'FAS')
PARAM=OpenSeismoMatlab(DT,XGTT,'BUTTERWORTHHIGH',BORDER,FLC)
PARAM=OpenSeismoMatlab(DT,XGTT,'BUTTERWORTHLOW',BORDER,FHC)
PARAM=OpenSeismoMatlab(DT,XGTT,'IDA',T,LAMBDAF,IM_DM,M,UY,PYSF,...
KSI,ALGID,U0,UT0,RINF,MAXTOL,JMAX,DAK)
Omit or set as empty ([]) the input arguments for which default
values are desired.
Description
This function calculates the seismic parameters, develops various
spectra and performs various analyses from an acceleration time
history. More specifically, it calculates the following:
1) Peak ground acceleration
2) Effective peak ground acceleration
3) Peak ground velocity
4) Peak ground displacement
5) Total cumulative energy and normalized cumulative energy vs time
6) Significant duration D_5_95 according to Trifunac & Brady (1975)
7) Significant duration D_5_75
8) Total Arias intensity (Ia)
9) Velocity time history (with baseline correction or not)
10) Displacement time history (with baseline correction or not)
11) Resampled acceleration time history (i.e. the input acceleration
time history with modified time step size)
12) Linear elastic pseudo-acceleration response spectrum
13) Linear elastic pseudo-velocity response spectrum
14) Linear elastic displacement response spectrum
15) Linear elastic velocity response spectrum
16) Linear elastic acceleration response spectrum
17) Rigid plastic sliding displacement response spectrum
18) Rigid plastic sliding velocity response spectrum
19) Rigid plastic sliding acceleration response spectrum
20) Constant ductility displacement response spectrum
21) Constant ductility velocity response spectrum
22) Constant ductility acceleration response spectrum
23) Fourier amplitude spectrum
24) Mean period (Tm)
25) Lowpass Butterworth-filtered acceleration time history
26) Highpass Butterworth-filtered acceleration time history
27) Incremental Dynamic Analysis (IDA) of SDOF system excited with
the input acceleration time history
28) Spectral intensity according to Housner (1952)
29) Spectral intensity according to Nau & Hall (1984)
Depending on the value of SW, which determines the type of analysis
that OpenSeismoMatlab performs, various additional parameters are
needed as input by the user. All possible syntaxes appear above.
Input parameters
DT [double(1 x 1)] is the size of the time step of the input
acceleration time history xgtt.
XGTT [double(:inf x 1)] is the input acceleration time history.
XGT [double(:inf x 1)] is the input velocity time history.
SW [char(1 x :inf)] is a string which determines which parameters,
spectras or analyses of the input acceleration time history will
be calculated. SW can take one of the following values (strings
are case insensitive):
'TIMEHIST': the displacement, velocity and acceleration time
histories are calculated.
'SINCRESAMPLE': the acceleration time history with modified time
step size is calculated through sinc resampling.
'PGA': The peak ground acceleration is calculated.
'PGV': The peak ground velocity is calculated.
'PGD': The peak ground displacement is calculated.
'ARIAS': The total cumulative energy, significant duration
D_5_95 according to Trifunac & Brady (1975), significant
duration D_5_75 and Arias intensity are calculated.
'PULSEDECOMP': the (velocity) time history is decomposed into a
pulse and a residual motion
'ELRS': The linear elastic response spectra and pseudospectra are
calculated.
'RPSRS': The rigid plastic sliding response spectra are
calculated.
'CDRS': The constant ductility response spectra are calculated.
'CSRS': The constant strength response spectra are calculated.
'IDA': Incremental Dynamic Analysis of an elastoplastic SDOF
system excited by the input acceleration time history is
performed.
'FAS': The Fourier amplitude spectrum and the mean period are
calculated.
'BUTTERWORTHHIGH': The high-pass Butterworth filtered
acceleration time history is calculated.
'BUTTERWORTHLOW': The low-pass Butterworth filtered
acceleration time history is calculated.
'EPGA': Effective Peak Ground Acceleration.
'SIH1952': Spectral Intensity according to Housner (1952).
'SINH1984': Spectral Intensity according to Nau & Hall (1984).
Additional required parameters
ALGID [char(1 x :inf)] is the algorithm to be used for the time
integration, if applicable. It can be one of the following
strings for superior optimally designed algorithms (strings are
case sensitive):
'generalized a-method': The generalized a-method (Chung &
Hulbert, 1993)
'HHT a-method': The Hilber-Hughes-Taylor method (Hilber,
Hughes & Taylor, 1977)
'WBZ': The Wood–Bossak–Zienkiewicz method (Wood, Bossak &
Zienkiewicz, 1980)
'U0-V0-Opt': Optimal numerical dissipation and dispersion
zero order displacement zero order velocity algorithm
'U0-V0-CA': Continuous acceleration (zero spurious root at
the low frequency limit) zero order displacement zero order
velocity algorithm
'U0-V0-DA': Discontinuous acceleration (zero spurious root at
the high frequency limit) zero order displacement zero order
velocity algorithm
'U0-V1-Opt': Optimal numerical dissipation and dispersion
zero order displacement first order velocity algorithm
'U0-V1-CA': Continuous acceleration (zero spurious root at
the low frequency limit) zero order displacement first order
velocity algorithm
'U0-V1-DA': Discontinuous acceleration (zero spurious root at
the high frequency limit) zero order displacement first order
velocity algorithm
'U1-V0-Opt': Optimal numerical dissipation and dispersion
first order displacement zero order velocity algorithm
'U1-V0-CA': Continuous acceleration (zero spurious root at
the low frequency limit) first order displacement zero order
velocity algorithm
'U1-V0-DA': Discontinuous acceleration (zero spurious root at
the high frequency limit) first order displacement zero order
velocity algorithm
'Newmark ACA': Newmark Average Constant Acceleration method
'Newmark LA': Newmark Linear Acceleration method
'Newmark BA': Newmark Backward Acceleration method
'Fox-Goodwin': Fox-Goodwin formula
Default value 'U0-V0-Opt'.
BASELINESW [logical(1 x 1)] determines if baseline correction will be
applied for the calculation of the various time histories.
BORDER [double(1 x 1)] is the order of the Butterworth filter that is
applied for filtering of the acceleration time history.
CF [double(1:numSDOFs x 1)] contains the values of the Coulomb
friction coefficient for which the response spectra are
requested. numSDOFs is the number of SDOF oscillators being
analysed to produce the spectra.
DAK [double(1 x 1)] is the infinitesimal acceleration for the
calculation of the derivetive required for the convergence of the
Newton-Raphson iteration.
DTI [double(1 x 1)] is the new time step size for resampling of the
input acceleration time history.
DTTOL [double(1 x 1)] is the tolerance for resampling of the input
acceleration time history. For a given eigenperiod T, resampling
takes place if DT/T>dtTol. Default value 0.02.
FHC [double(1 x 1)] is the high cutoff frequency for the low-pass
Butterworth filter.
FLC [double(1 x 1)] is the low cutoff frequency for the high-pass
Butterworth filter.
FYR [double(1 x 1)] is the yield strength ratio (yield shear to
weight, V/W).
IM_DM [char(1 x :inf)] is the Intensity Measure (IM) - Damage Measure
(DM) pair that is to be calculated from the incremental dynamic
analysis. IM_DM can take one of the following values (strings are
case insensitive):
'SA_MU': Spectral acceleration-ductility
'PGD_MU': Peak displacement-ductility
'PGV_MU': Peak velocity-ductility
'PGA_MU': Peak acceleration-ductility
'SA_DISP': Spectral acceleration-displacement
'PGD_DISP': Peak displacement-displacement
'PGV_DISP': Peak velocity-displacement
'PGA_DISP': Peak acceleration-displacement
'SA_VEL': Spectral acceleration-velocity
'PGD_VEL': Peak displacement-velocity
'PGV_VEL': Peak velocity-velocity
'PGA_VEL': Peak acceleration-velocity
'SA_ACC': Spectral acceleration-acceleration
'PGD_ACC': Peak displacement-acceleration
'PGV_ACC': Peak velocity-acceleration
'PGA_ACC': Peak acceleration-acceleration
JMAX [double(1 x 1)] is the maximum number of iterations per
increment. If JMAX=0 then iterations are not performed and the
MAXTOL parameter is not taken into account.
KSI [double(1 x 1)] is the fraction of critical viscous damping.
LAMBDAF [double(:inf x 1)] contains the values of the scaling factor
(lambda factor) for the incremental dynamic analysis.
M [double(1 x 1)] is the mass of the SDOF oscillator.
MAXTOL [double(1 x 1)] is the maximum tolerance of convergence of the
Full Newton Raphson method for numerical computation of
acceleration.
MU [double(1 x 1)] is the specified ductility for which the constant
ductility response spectra are calculated.
NSCALES [double(1 x 1)] is the number of pulse period values between
TPMIN and TPMAX to be considered for the continuous 1-D wavelet
transform of XGT
PYSF [double(1 x 1)] is the post-yield stiffness factor, i.e. the
ratio of the postyield stiffness to the initial stiffness. PYSF=0
is not recommended for simulation of an elastoplastic system; a
small positive value is always suggested due to numerical
reasons. PYSF is ignored if MU=1. Default value 0.01.
RINF [double(1 x 1)] is the minimum absolute value of the eigenvalues
of the amplification matrix. For the amplification matrix see
eq.(61) in Zhou & Tamma (2004). Default value 0.
T [double(:inf x 1)] contains the values of eigenperiods for
which the response spectra are requested. Its length is the
number of SDOF oscillators being analysed to produce the spectra.
T must be a vector if SW='ELRS' or SW='CDRS'. T must be scalar if
SW='IDA'.
TPMAX [double(1 x 1)] is the maximum pulse period to be considered
for the continuous 1-D wavelet transform of XGT
TPMIN [double(1 x 1)] is the minimum pulse period to be considered
for the continuous 1-D wavelet transform of XGT
U0 [double(1 x 1)] is the initial displacement of the SDOF
oscillator.
UT0 [double(1 x 1)] is the initial velocity of the SDOF oscillator.
UY [double(1 x 1)] is the yield displacement of the SDOF oscillator.
WNAME [char(1 x :inf)] is the wavelet family short name to be used
for the decomposition of the velocity time history. See the
Matlab function waveinfo.m for more details.
Output parameters
PARAM (structure) has the following fields:
PARAM.acc [double(:inf x 1)] Acceleration time history
PARAM.arias [double(1 x 1)] Total Arias intensity (Ia)
PARAM.CDPSa [double(:inf x 1)] Constant ductility
pseudo-acceleration response spectrum
PARAM.CDPSv [double(:inf x 1)] Constant ductility pseudo-velocity
response spectrum
PARAM.CDSa [double(:inf x 1)] Constant ductility acceleration
response spectrum
PARAM.CDSd [double(:inf x 1)] Constant ductility displacement
response spectrum
PARAM.CDSv [double(:inf x 1)] Constant ductility velocity
response spectrum
PARAM.disp [double(:inf x 1)] Displacement time history
param.DM [double(:inf x 1)] is the damage measure (DM) of the
incremental dynamic analysis
PARAM.Ecum [double(1 x 1)] Total cumulative energy
PARAM.EcumTH [double(:inf x 1)] Normalized cumulative
energy vs time
PARAM.EPGA [double(1 x 1)] Effective peak ground acceleration
PARAM.FAS [double(1:2^(nextpow2(length(xgtt))-1) x 1)] Fourier
amplitude spectrum
PARAM.Fm [double(1 x 1)] Mean frequency (Fm)
PARAM.fyK [double(:inf x 1)] yield limit that each SDOF must have
in order to attain ductility equal to PARAM.muK.
param.IM [double(:inf x 1)] is the intensity measure (IM) of the
incremental dynamic analysis
PARAM.iterK [double(:inf x 1)] number of iterations needed for
convergence for each period (each SDOF).
PARAM.muK [double(:inf x 1)] achieved ductility for each period
(each SDOF).
PARAM.PGA [double(1 x 1)] Peak ground acceleration
PARAM.PGD [double(1 x 1)] Peak ground displacement
PARAM.PGV [double(1 x 1)] Peak ground velocity
PARAM.PredPeriod [double(1 x 1)] Predominant period of the PSa
spectrum
PARAM.PredPSa [double(1 x 1)] Predominant acceleration of the PSa
spectrum
PARAM.PSa [double(:inf x 1)] Linear elastic pseudo-acceleration
response spectrum
PARAM.PSv [double(:inf x 1)] Linear elastic pseudo-velocity
response spectrum
PARAM.pulseTH [double(:inf x 1)] Time history of the pulse
contained in velocity time history
PARAM.resTH [double(:inf x 1)] Time history of the residual
motion after subtracting the pulse from the velocity time
history
PARAM.RPSSa [double(:inf x 1)] Rigid plastic sliding response
spectral acceleration
PARAM.RPSSd [double(:inf x 1)] Rigid plastic sliding response
spectral displacement
PARAM.RPSSv [double(:inf x 1)] Rigid plastic sliding response
spectral velocity
PARAM.Sa [double(:inf x 1)] Linear elastic acceleration response
spectrum
PARAM.Sd [double(:inf x 1)] Linear elastic displacement response
spectrum
PARAM.SI [double(1 x 1)] Spectral intensity
PARAM.Siev [double(:inf x 1)] Linear elastic relative input
energy equivalent velocity spectrum
PARAM.Sv [double(:inf x 1)] Linear elastic velocity response
spectrum
PARAM.t_5_75 [double(1 x 2)] Time instants at which 5% and 75% of
cumulative energy have occurred
PARAM.t_5_95 [double(1 x 2)] Time instants at which 5% and 95% of
cumulative energy have occurred
PARAM.Td_5_75 [double(1 x 1)] Time between when 5% and 75% of
cumulative energy has occurred
PARAM.Td_5_95 [double(1 x 1)] Time between when 5% and 95% of
cumulative energy has occurred (significant duration
according to Trifunac-Brady (1975))
PARAM.time [double(:inf x 1)] Time
PARAM.Tm [double(1 x 1)] Mean period (Tm)
PARAM.Tp [double(1 x 1)] Period of the pulse
PARAM.vel [double(:inf x 1)] Velocity time history
PARAM.wavCoefs [double(1 x 1)] Coefficient for the extracted
wavelet
PARAM.wavScale [double(1 x 1)] Scale at which the largest wavelet
was found
__________________________________________________________________________
Copyright (c) 2018-2023
George Papazafeiropoulos
Major, Infrastructure Engineer, Hellenic Air Force
Civil Engineer, M.Sc., Ph.D.
Email: gpapazafeiropoulos@yahoo.gr
_________________________________________________________________________