In Control parameter page, the user is allowed to set up basic parameters to control calculation. It includes step size setup, specify number of CPUs, blank mesh adaptive setup, implicit analysis parameters setup and restart file output control, etc. Control parameter setup interface is shown in Figure 8.2.95.
Figure 8.2.95 Basic Control Parameter Setup
8.2.7.1 GENERAL
TIME STEP SIZE: Allow the user to set up time step size. Default time step size is -1.2e-6.
NUMBER OF CPUs USED (NCPU): Define number of CPUs used in calculation. Default value is 1.
ADVANCED¡: Advanced setup for basic parameters. The interface is shown in Figure 8.2.96.
Figure 8.2.96 Basic Parameter Advanced Setup Interface
8.2.7.2 ADAPTIVE MESHING
TIMES (ENDTIME/ADPFREQ): Allow the user to set up the adaptive check time interval. Default time separation is to check every 40 cycles.
TOLERANCE IN DEGREE (ADPTOL): Set up angle change between elements during adaptive meshing. If angle change is greater than 5 degrees, the coarse elements are divided into fine elements.
MAX. REFINEMENT LEVELS (MAXLVL): Maximum refinement level allowed. Default level is 3. It means one element can mostly be divided into 4 elements after adaptive meshing.
ADVANCED¡: Advanced setup for adaptive meshing. The interface is shown in Figure 8.2.97.
Figure 8.2.97 Adaptive Advanced Parameters
8.2.7.3 DYNAMIC RELAXATION
CONVERGENCE TOLERANCE (DRTOL): Setup convergence tolerance during dynamic relaxation calculation. Default convergence tolerance is 0.01.
ADVANCED¡: Advanced parameter setup of dynamic relaxation. The interface is shown in Figure 8.2.98.
Figure 8.2.98 Advanced Parameters of Dynamic Relaxation Calculation
8.2.7.4 IMPLICIT ANALYSIS
INITIAL TIME STEP SIZE (DT0): Initial time step size of springback analysis. Default value is 0.001.
NUMBER OF IMPLICIT STEP (NSBS): Number of implicit step. If the value is 1, it indicates single step implicit analysis. If the value is greater than 1, multiple implicit analysis will be used.
ADVANCED¡: Advanced parameter setup of implicit analysis. See Figure 8.2.99 for the list of parameters.
Figure 8.2.99 Advanced Parameter Setup of Implicit Analysis
8.2.7.5 RESTART
WRITE RESTART: The user may use this option to output one or several restart files. The interface is shown in Figure 8.2.100.
Figure 8.2.100 Restart Advanced Parameter Setup
Detailed description of restart can be found in LS-DYNA User¡¯s Manual.