Defining a Reaction/ Internal Force Constraint | |||||
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Define an Internal Force Constraint in Tosca ANSA® environment
Repeat for EL_GROUP_DEF where an element group shall be chosen, see the following figure.
Internally in SIMULIA Tosca Structure, a separate design response for each pair (node, element) is created, where the node belongs to the chosen node group and to the element (that itself belongs to the chosen element group). In the example, 32 nodes are connected to the cweld elements. Since there are two load cases, 64 design responses are produced in SIMULIA Tosca Structure.
Define an Internal Force Constraint in Tosca Structure.gui
- Define an internal force constraint in Tosca Structure.gui as shown in the following figure:
Result and Convergence
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Objective function plot (relative material volume) is presented in the next figure:
Internal force constraint values are pictured in the following figure:
Displacement constraint values are shown in the next figure:
The last figure presents the result of the optimization under force constraints in the spot weld elements:
SIMULIA Tosca Structure Parameter File
- The commands in the parameter file look like follows:
DRESP ID_NAME = DRESP_VOLUME TYPE = VOLUME DEF_TYPE = SYSTEM GROUP_OPER = Sum EL_GROUP = ALL_ELEMENTS END_ OBJ_FUNC ID_NAME = MINIMIZE_VOLUME TARGET = MIN DRESP = DRESP_VOLUME, , END_ GROUP_DEF ID_NAME = CWELD_NODES TYPE = NODE FORMAT = LIST LIST_BEGIN 5291, 4055, 5295, 4051, 5299, 4047, 5303, 4043, 5501, 4026, 5505, 4030, 5509, 4034, 5513, 4038, 5186, 4685, 5190, 4681, 5194, 4677, 5198, 4673, 5396, 4656, 5400, 4660, 5404, 4664, 5408, 4668 END_ GROUP_DEF ID_NAME = CWELD_ELEMENTS TYPE = ELEM FORMAT = LIST LIST_BEGIN 100000-100015 END_ DRESP ID_NAME = DRESP_INT_FORCE_ABS TYPE = INTERNAL_FORCE_ABS DEF_TYPE = SYSTEM GROUP_OPER = Max EL_GROUP = CWELD_ELEMENTS ND_GROUP = CWELD_NODES END_
CONSTRAINT ID_NAME = CONSTRAINT_INT_FORCE_ABS DRESP = DRESP_INT_FORCE_ABS MAGNITUDE = ABS LE_VALUE = 15 END_ DRESP ID_NAME = DRESP_DISP_LC11 DEF_TYPE = SYSTEM TYPE = DISP_ABS NODE = 3900 LC_SET = ALL,11,All GROUP_OPER = Max END_ DRESP ID_NAME = DRESP_DISP_LC12 DEF_TYPE = SYSTEM TYPE = DISP_ABS NODE = 4530 LC_SET = ALL,12,All GROUP_OPER = Max END_ CONSTRAINT ID_NAME = MAX_DISP_LC11 MAGNITUDE = ABS DRESP = DRESP_DISP_LC11 LE_VALUE = 0.003 END_ CONSTRAINT ID_NAME = MAX_DISP_LC12 MAGNITUDE = ABS DRESP = DRESP_DISP_LC12 LE_VALUE = 0.003 END_
OPTIMIZE ID_NAME = TOPOLOGY_OPTIMIZATION DV = DESIGN_VARIABLES OBJ_FUNC = MINIMIZE_VOLUME CONSTRAINT = MAX_DISP_LC11 DVCON = DVCON_FROZEN STRATEGY = TOPO_SENSITIVITY CONSTRAINT = MAX_DISP_LC12 CONSTRAINT = CONSTRAINT_INT_FORCE_ABS END_ OPT_PARAM ID_NAME = MY_PARAMETERS OPTIMIZE = TOPOLOGY_OPTIMIZATION DENSITY_UPDATE = CONSERVATIVE STOP_CRITERION_DENSITY = 0.001 END_