A stop condition is defined by assigning a logical variable (LOGICAL) to an optimization task (OPTIMIZE). The stop condition can be specifically addressed with its user defined name (ID_NAME). STOP ID_NAME = stop_name LOGICAL = logical_name OPTIMIZE = opt_grp_name END_ The stop condition ends the optimization for the selected optimization group when the value for the assigned logical variable is TRUE. If several STOP conditions have been defined for an optimization group, the optimization for this group is ended when one of the stop conditions is fulfilled (corresponds to a logical OR condition). The logical variable can vary significantly. Before using the STOP command, numerical and logical variables must be defined with the VARIABLE and LOGICAL commands. The flexibility is achieved by using various logical variables as the stop criteria. Logical operations AND or OR can also be included in the STOP command by defining the logical variables. For shape optimization, typical stop conditions can be defined more directly by an enhanced stop command: STOP ID_NAME = stop_command MOD_NDGR = all_nodes MOD_TYPE = MAX, CTRL_INP_SHAPE MOD_OPER = LE MOD_REF = 0.01, MULT, FIRST OPTIMIZE = run END_ In this case, the optimization task "run" should stop when the maximum equivalent stress (CTRL_INP_SHAPE) of the node group all_nodes is smaller than 1% of the maximum equivalent stress of the first iteration. Using this enhanced stop command, the extraction of variables and their logical comparison is performed internally by SIMULIA Tosca Structure and need no longer be specified manually by the user. For a detailed description of the several items, refer to the commands manual. If desired, the global upper limit for the maximum number of iterations can be set with a separate, brief command. In this case, a definition of logical variables is not required. STOP ID_NAME = STOP_CONDITION ITER_MAX = <value> END_ A global stop condition is integrated in the system to limit the maximum number of iterations for safety reasons. This stop condition is always active. The default value for the maximum number of iterations is set to 40. As an example, the command STOP ID_NAME = STOP_CONDITION ITER_MAX = 55 END_ increases the maximum number of iterations.
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