Product: Abaqus/Standard
User subroutine UAMP:
allows you to define the current value of an amplitude definition as a function of time;
can be used to model control engineering aspects of your system when sensors are used (sensor values are from the beginning of the increment);
can use a predefined number of state variables in their definition; and
can optionally compute the derivatives and integrals of the amplitude function.
The solution dependence introduced in this user subroutine is explicit: all data passed in the subroutine for information or to be updated are values at the beginning of that increment.
SUBROUTINE UAMP(
* ampName, time, ampValueOld, dt, nProps, props, nSvars,
* svars, lFlagsInfo,
* nSensor, sensorValues, sensorNames, jSensorLookUpTable,
* AmpValueNew,
* lFlagsDefine,
* AmpDerivative, AmpSecDerivative, AmpIncIntegral,
* AmpDoubleIntegral)
C
INCLUDE 'ABA_PARAM.INC'
C time indices
parameter (iStepTime = 1,
* iTotalTime = 2,
* nTime = 2)
C flags passed in for information
parameter (iInitialization = 1,
* iRegularInc = 2,
* iCuts = 3,
* ikStep = 4,
* nFlagsInfo = 4)
C optional flags to be defined
parameter (iComputeDeriv = 1,
* iComputeSecDeriv = 2,
* iComputeInteg = 3,
* iComputeDoubleInteg = 4,
* iStopAnalysis = 5,
* iConcludeStep = 6,
* nFlagsDefine = 6)
dimension time(nTime), lFlagsInfo(nFlagsInfo),
* lFlagsDefine(nFlagsDefine)
dimension jSensorLookUpTable(*)
dimension sensorValues(nSensor), svars(nSvars), props(nProps)
character*80 sensorNames(nSensor)
character*80 ampName
user coding to define AmpValueNew, and
optionally lFlagsDefine, AmpDerivative, AmpSecDerivative,
AmpIncIntegral, AmpDoubleIntegral
RETURN
ENDlFlagsDefine
Integer flag array to determine whether the computation of additional quantities is necessary or to set step continuation requirements.
| lFlagsDefine(iComputeDeriv) | If set to 1, you must provide the computation of the amplitude derivative. The default is 0, which means that Abaqus computes the derivative automatically. |
| lFlagsDefine(iComputeSecDeriv) | If set to 1, you must provide the computation of the amplitude second derivative. The default is 0, which means that Abaqus computes the second derivative automatically. |
| lFlagsDefine(iComputeInteg) | If set to 1, you must provide the computation of the amplitude incremental integral. The default is 0, which means that Abaqus computes the incremental integral automatically. |
| lFlagsDefine(iComputeDoubleInteg) | If set to 1, you must provide the computation of the amplitude incremental double integral. The default is 0, which means that Abaqus computes the incremental integral automatically. |
| lFlagsDefine(iStopAnalysis) | If set to 1, the analysis will be stopped and an error message will be issued. The default is 0, which means that Abaqus will not stop the analysis. |
| lFlagsDefine(iConcludeStep) | If set to 1, Abaqus will conclude the step execution and advance to the next step (if a next step exists). The default is 0. |
svars
An array containing the values of the solution-dependent state variables associated with this amplitude definition. The number of such variables is nsvars (see above). You define the meaning of these variables.
This array is passed into UAMP containing the values of these variables at the start of the current increment. In most cases they should be updated to be the values at the end of the increment.
AmpDerivative
Current value of the amplitude derivative.
AmpSecDerivative
Current value of the amplitude second derivative.
AmpIncIntegral
Current value of the amplitude incremental integral.
AmpDoubleIntegral
Current value of the amplitude incremental double integral.
ampName
User-specified amplitude name, left justified.
time(iStepTime)
Current value of step time or frequency.
time(iTotalTime)
Current value of total time.
ampValueOld
Old value of the amplitude from the previous increment.
dt
Time increment.
props
User-specified array of material constants associated with this amplitude definition.
nProps
User-defined number of material constants associated with this amplitude definition.
nSvars
User-defined number of solution-dependent state variables associated with this amplitude definition.
lFlagsInfo
Integer flag array with information regrading the current call to UAMP.
| lFlagsInfo(iInitialization) | This flag is equal to 1 if UAMP is called from the initialization phase of the first analysis step and is set to 0 otherwise. |
| lFlagsInfo(iRegularInc) | This flag is equal to 1 if UAMP is called from a regular increment and is set to 0 if called from the initialization phase of the first analysis step. |
| lFlagsInfo(iCuts) | Number of cutbacks in this increment. |
| lFlagsInfo(ikStep) | Step number. |
nSensor
Total number of sensors in the model.
sensorValues
Array with sensor values at the end of the previous increment. Each sensor value corresponds to a history output variable associated with the output database request defining the sensor.
sensorNames
Array with user-defined sensor names in the entire model, left justified. Each sensor name corresponds to a sensor value provided with the output database request. All names will be converted to uppercase characters if lowercase or mixed-case characters were used in their definition.
jSensorLookUpTable
Variable that must be passed into the utility functions IGETSENSORID and GETSENSORVALUE.
c user amplitude subroutine
Subroutine UAMP(
C passed in for information and state variables
* ampName, time, ampValueOld, dt, nProps, props, nSvars,
* svars, lFlagsInfo,
* nSensor, sensorValues, sensorNames,
* jSensorLookUpTable,
C to be defined
* ampValueNew,
* lFlagsDefine,
* AmpDerivative, AmpSecDerivative, AmpIncIntegral,
* AmpDoubleIntegral)
include 'aba_param.inc'
C svars - additional state variables, similar to (V)UEL
dimension sensorValues(nSensor), svars(nSvars),
* props(nProps)
character*80 sensorNames(nSensor)
character*80 ampName
C time indices
parameter( iStepTime = 1,
* iTotalTime = 2,
* nTime = 2)
C flags passed in for information
parameter( iInitialization = 1,
* iRegularInc = 2,
* iCuts = 3,
* ikStep = 4,
* nFlagsInfo = 4)
C optional flags to be defined
parameter( iComputeDeriv = 1,
* iComputeSecDeriv = 2,
* iComputeInteg = 3,
* iComputeDoubleInteg = 4,
* iStopAnalysis = 5,
* iConcludeStep = 6,
* nFlagsDefine = 6)
parameter( tStep=0.18d0, tAccelerateMotor = .00375d0,
* omegaFinal=23.26d0,
* zero=0.0d0, one=1.0d0, two=2.0d0, four=4.0d0)
dimension time(nTime), lFlagsInfo(nFlagsInfo),
* lFlagsDefine(nFlagsDefine)
dimension jSensorLookUpTable(*)
lFlagsDefine(iComputeDeriv) = 1
lFlagsDefine(iComputeSecDeriv) = 1
lFlagsDefine(iComputeInteg) = 1
lFlagsDefine(iComputeDoubleInteg) = 1
c get sensor value
vTrans_CU1 = GetSensorValue('HORIZ_TRANSL_MOTION',
* jSensorLookUpTable,
* sensorValues)
if (ampName(1:22) .eq. 'MOTOR_WITH_STOP_SENSOR' ) then
if (lFlagsInfo(iInitialization).eq.1) then
AmpSecDerivative = zero
AmpDerivative = omegaFinal/tAccelerateMotor
ampValueNew = zero
AmpIncIntegral = zero
AmpDoubleIntegral = zero
svars(1) = zero
svars(2) = zero
else
tim = time(iStepTime)
c ramp up the angular rot velocity of the
c electric motor
c after which hold constant
if (tim .le. tAccelerateMotor) then
AmpSecDerivative = zero
AmpDerivative = omegaFinal/tAccelerateMotor
ampValueNew = omegaFinal*tim/tAccelerateMotor
AmpIncIntegral = dt*(ampValueOld+ampValueNew)/
two
AmpDoubleIntegral = dt**2*(ampValueOld+ampValueNew)/
four
else
AmpSecDerivative = zero
AmpDerivative = zero
ampValueNew = omegaFinal
AmpIncIntegral = dt*(ampValueOld+ampValueNew)/
two
AmpDoubleIntegral = dt**2*(ampValueOld+ampValueNew)/
four
end if
c retrieve old sensor value
vTrans_CU1_old = svars(1)
c detect a zero crossing and count the number of
c crossings
if (vTrans_CU1_old*vTrans_CU1 .le. zero .and.
* tim .gt. tAccelerateMotor ) then
svars(2) = svars(2) + one
end if
nrCrossings = int(svars(2))
c stop the motor if sensor crosses zero the second
time
if (nrCrossings.eq.2) then
ampValueNew = zero
lFlagsDefine(iConcludeStep)=1
end if
c store sensor value
svars(1) = vTrans_CU1
end if
end if
return
end