TINTP
TINTP, GAMMA,
ALPHA, DELTA,
THETA, OSLM,
TOL, OSLM2,
--, AVSMOOTH,
ALPHAF, ALPHAM
Defines transient integration parameters.
GAMMAAmplitude decay factor for 2nd order transient integration, for example, structural dynamics (used only if
ALPHA,DELTA,ALPHAF, andALPHAMare blank, see "Notes"). Defaults to 0.005.Alternatively, you can input the application type for the analysis using one of the following labels. In this case, the program automatically sets the transient dynamic solver algorithm and settings based on the intended application. For more information, see Transient Dynamic Analysis Settings Based on Application in the Structural Analysis Guide.
IMPA
—
Impact application.
HISP
—
High speed dynamic application.
MOSP
—
Moderate speed dynamic application.
LOSP
—
Low speed dynamic application.
QUAS
—
Quasi-static application.
ALPHA2nd order transient integration parameter (used only if
GAMMAis blank). Defaults to 0.2525.DELTA2nd order transient integration parameter (used only if
GAMMAis blank). Defaults to 0.5050.THETA1st order transient (for example, thermal transient) integration parameter. Defaults to 1.0.
OSLMSpecifies the oscillation limit criterion for automatic time stepping of 1st order transients (for example, thermal transients). Defaults to 0.5 with a tolerance of
TOL.TOLTolerance applied to
OSLM. Defaults to 0.0.OSLM2Specifies the oscillation limit for automatic time stepping of second order transients (for example, structural transients). The automatic time stepping algorithm will adjust to have approximately the specified number of points per cycle. You can specify a negative number (for example, -1) to define a time increment that is independent of the oscillation limit.
--Unused field.
AVSMOOTHSmoothing flag option:
0
—
Include smoothing of the velocity (1st order system) or the acceleration (2nd order system) (default).
1
—
Do not include smoothing.
ALPHAFInterpolation factor in HHT algorithm for force and damping terms (used only if
GAMMAis blank). Defaults to 0.005.ALPHAMInterpolation factor in HHT algorithm for inertial term (used only if
GAMMAis blank). Defaults to 0.0.
Command Default
GAMMA defaults to 0.005, which is the same as choosing the High
Speed application (GAMMA = HISP). All other fields default as
described above.
Notes
Used to define the transient integration parameters. For more information on transient integration parameters, refer to Transient Analysis in the Theory Reference.
For a full structural transient analysis, you may
choose between the Newmark and HHT time integration methods (see the TRNOPT
command). In this case, if GAMMA is input and the integration
parameters ALPHA, DELTA,
ALPHAF, and ALPHAM are left blank, the
program calculates the integration parameters, according to Equation 15–14 and Equation 15–18.
Alternatively, you can input these integration parameters directly on this command. However, for
the unconditional stability and second order accuracy of the time integration, these parameters
should satisfy a specific relationship, as described in Description of Structural and Other Second Order Systems of the Mechanical APDL Theory Reference.
For mode-superposition transient analysis, the integration parameters
ALPHA and DELTA are always calculated by
the program from the GAMMA value, according to Equation 15–14. If an ALPHA,
DELTA pair has been specified with GAMMA
left blank, the input values are ignored, and integration parameters
ALPHA, DELTA are calculated with
GAMMA = 0.
This command is also valid in PREP7.