Supported Element Types

The analysis model can contain arbitrary element types and supplementary options.

Only design nodes that are attached to certain element types can be used in shape and bead optimization, see About Design Variables (DV_SHAPE) and Design Variables (DV_BEAD) for details. All other element types are allowed if they are not modified during the optimization. Only certain element types for defining the restriction areas of elements are permitted.

Some further restrictions might apply regarding specific design responses. Check remarks for this.


Tosca Structure Element Type	MSC Nastran® Element Type	Design Element
SOLID_BRICK_8	CHEXA	C, S, STS, F
SOLID_BRICK_20	CHEXA	C, S, F
SOLID_TETRA_4	CTETRA4	C, S, STS, F
SOLID_TETRA_10	CTETRA10	C, S, STS, F
SOLID_PENTA_6	CPENTA	C, S, F
SOLID_PENTA_15	CPENTA	C, S, F
SHELL_QUAD_4	CQUAD4 CQUAD8 CQUAD CQUADR CSHEAR CQUADX	C, S, F C, S, F C C, S, F C,S, F
SHELL_QUAD_8	CQUAD8 CQUAD CQUADX	C, S, F C
SHELL_TRIANG_3	CTRIA3 CTRIA6 CTRIAR CTRIAX CTRIAX6	C, S, F C, S C, S, F C
SHELL_TRIANG_6	CTRIA6 CTRIAX CTRIAX6	C, S, F C
BEAM_3D	CBAR CBEAM CBEND CBUSH	can be used as restriction element for shape optimizations
GAP_2_ND	CGAP
MASS_1	CONM1 CMASS1
DUMMY_ELEM_TYPE	all not supported element types
C=allowed for controller-based optimization (bead, shape, and topology) S=allowed for sensitivity-based topology optimization STS = allowed for sensitivity-based shape optimization using internal sensitivity calculation routines F=allowed for the design responses that use the element-based reaction and internal forces

More solver-specific information about the sensitivity-based algorithm is found in Remarks for Sensitivity-Based Optimizations. For sensitivity-based bead optimization, see Special Remarks Using Sensitivity-Based Algorithm.

Important:

Elements with linear or quadratic element formulations are supported. Mixed elements types are not permitted. A model can contain linear as well as quadratic elements.
Shell structures are optimized in form and not in thickness in shape optimization. This means that the "shell edges" need to be modified, not the shell layers.
Shell elements are not admitted for stresses in topology optimization.