This option is used to provide a direct cyclic procedure for nonlinear, non-isothermal quasi-static analysis in ABAQUS/Standard.
Product: ABAQUS/Standard
Type: History data
Level: Step
Set this parameter equal to the maximum difference in the creep strain increment calculated from the creep strain rates based on conditions at the beginning and on conditions at the end of the increment, thus controlling the time integration accuracy of the creep integration.
This parameter can be used in conjunction with the *TIME POINTS option. In this case ABAQUS/Standard will ensure the response will also be evaluated at each time point specified on the *TIME POINTS option.
If both this parameter and the DELTMX parameter are omitted, fixed time stepping will be used, with a constant time increment equal to the initial time increment or by following precisely the time points specified on the *TIME POINTS option.
Set CONTINUE=YES to specify that the current *DIRECT CYCLIC step is a continuation of the previous direct cyclic step. The displacement solution in the Fourier series obtained in the previous *DIRECT CYCLIC step is then used as the starting values for the current step.
Set CONTINUE=NO (default) to reset all the displacement Fourier coefficients to zero, thus allowing application of cyclic loading conditions that are very different from those in the previous direct cyclic step.
Set this parameter equal to the maximum temperature change to be allowed in an increment during a direct cyclic analysis. ABAQUS/Standard will restrict the time increment to ensure that this value will not be exceeded at any node during any increment of the step.
This parameter can be used in conjunction with the *TIME POINTS option. In this case ABAQUS/Standard will ensure the response will also be evaluated at each time point specified on the *TIME POINTS option.
If both this parameter and the CETOL parameter are omitted, fixed time stepping will be used, with a constant time increment equal to the initial time increment or by following precisely the time points specified on the *TIME POINTS option.
First (and only) line:
Initial time increment. If this entry is omitted, a default value of 0.1 times the single loading cycle period is assumed. If automatic incrementation is used, this should be a reasonable suggestion for the initial increment size and will be adjusted as necessary. If direct incrementation is used, this entry will be used as the constant time incrementation or will be ignored if the *TIME POINTS option is specified.
Time of a single loading cycle.
Minimum time increment allowed. This entry is used only if the CETOL or DELTMX parameter is specified. If this entry is omitted, a default value of the smaller of the suggested initial time increment or 10–5 times the single loading cycle period is assumed.
Maximum time increment allowed. This entry is used only if the CETOL or DELTMX parameter is specified. If this entry is omitted, the upper limit is equal to 0.1 times the single loading cycle period.
Initial number of terms in the Fourier series. The value must be greater than 0 and less than 100. It cannot be greater than half of the time of a single loading cycle divided by the initial time increment. If the *TIME POINTS option is used, the number of terms in the Fourier series must be less than half of the number of time points specified. ABAQUS/Standard will automatically adjust the number of Fourier terms used in the analysis if such a condition is not satisfied. The default is 11.
Maximum number of terms in the Fourier series. It must be greater than 0 and less than 100. The default is 25.
Increment in number of terms in the Fourier series. The default is 5.
Maximum number of iterations allowed in a step. The default is 200.