HMIN_opticontrol_write()
Writes optimization control parameters to HyperMesh.
Syntax
void HMIN_opticontrol_write(HM_entityidtype id,char *name, int desmax, char desmaxtoggle,double mindim,char mindimtoggle,int minmeth, char minmethtoggle, double matinit,char matinittoggle,double mindens, char mindenstoggle,double discrete,char discretetoggle,int checker, char checkertoggle,int mmcheck,char mmchecktoggle,double objtol, char objtoltoggle,double delsiz,char delsiztoggle,double delshp, char delshptoggle,double deltop,char deltoptoggle, int * nastran_toggles, int * nastran_int_controls, double * nastran_real_controls )Type
HyperMesh hminlib Function
Description
Writes optimization control parameters to HyperMesh.
Inputs
- id
- The ID of the OptiStruct.
- name
- The name of the OptiStruct.
- desmax
- Maximum number of design iterations ( default = 30, if MINDIM is defined, default = 80).
- desmaxtoggle
- Flag to indicate that desmax is used (0: not used, 1: used).
- mindim
- Specifies the minimum diameter of members formed in a topology optimization. This command is used to eliminate small members. It also eliminates checkerboard results. The method is defined by MINMETH (real > 0.0, default = no minimum member size control).
- mindimtoggl
- Flag to indicate that mindim is used (0: not used, 1: used).
- minmeth
- Specifies the method of minimum member size control. Method 2 is set as default since it achieves more discrete solutions for most examples (1 or 2).
- minmethoggle
- Flag to indicate that minmeth is used (0: not used, 1: used).
- matinit
- This parameter declares the initial material fraction. For topology optimization runs with mass as the objective, default is 0.9. For runs with constrained mass, the default is reset to the constraint value. If mass is not the objective function and is not constrained, the default is 0.6. (between 0.0 and 1.0).
- matinittoggle
- Flag to indicate that matinit is used (0: not used, 1: used).
- mindens
- Minimum element material density. Sets a lower limit on the amount of material that can be assigned to any design element. Extremely low values for this parameter can result in an ill-conditioned stiffness matrix.
- mindenstoggle
- Flag to indicate that mindens is used (0: not used, 1: used).
- discrete
- Discreteness parameter. Influences the tendency for elements to converge to a material density of 0 or 1. Higher values decrease the number of elements that remain between 0 and 1. Recommended bounds are 0.0 and 2.0 for shells, or 3.0 for solids.
- discretetoggle
- Flag to indicate that discrete is used (0: not used, 1: used).
- checker
- Controls checkerboarding. ( 0,1 or 2, default = 0) Use 0 for no checkerboard control. Use 1 for global averaging over the entire design domain. This option generally yields a large number of semi-dense elements around fully dense elements. To reduce the number of semi-dense elements in the solution, restart the final iteration with checkerboard control off and run for 10-20 iterations. This may reintroduce some local checkerboarding. This method is used with plate/shell and solid design elements and is highly recommended for Tetra elements. Nodal densities are output to the .res file if this option is used. Use 2 for averaging at local areas identified as checkerboarded. Since averaging is only applied locally, a much smaller number of semi-dense elements are found in the final iteration compared to the global averaging method. This method applies only to shell design elements. If used in models with solid design elements, checkerboard control is not applied to solid elements.
- checkertoggle
- Flag to indicate that checker is used (0: not used, 1: used).
- mmcheck
- The use of this parameter will ensure a checkerboard free solution, although with the undesired side effect of achieving a solution that involves a large number of semi-dense elements, similar to the result of using checker=1. Therefore, use this parameter only when it is necessary. (0 or 1).
- mmchecktoggle
- Flag to indicate that mmchechk is used (0: not used, 1: used).
- objtol
- Relative convergence criterion. If relative change in the objective function between two design iterations is less than OBJTOL then optimization stops.
- objtoltoggle
- Flag to indicate that objtol is used (0: not used, 1: used).
- delsiz
- Fractional move limit for size design variables.
- delsiztoggle
- Flag to indicate that delsiz is used (0: not used, 1: used).
- delsshp
- Fractional move limit for topography/shape design variables. Defined as the fractional difference between the upper and lower bounds.
- delshptoggle
- Flag to indicate that delshp is used (0: not used, 1: used).
- deltop
- Fractional move limit for topology design variables.
- deltoptoggle
- Flag to indicate that delshp is used (0: not used, 1: used).
- nastran_toggles
- Toggle variables for Nastran optimization control parameters. If an element of the array above is set to zero, the optimization program does not take into account the settings for that variable. If the value for an element is 1, the optimization program uses the values in the arrays bellow instead of the default values.
- nastran_int_controls
- Integer type optimization control parameters for Nastran.
- nastran_real_controls
- Real type optimization control parameters for Nastran.
Example
The optimization control parameters for Nastran are grouped into an integer array and a real array in the following way:
Integer parameters
nastran_int_controls[0 ] : APPRCOD
nastran_int_controls[1 ] : DESMAX
nastran_int_controls[2 ] : IGMAX
nastran_int_controls[3 ] : IPRINT
nastran_int_controls[4 ] : IPRNT1
nastran_int_controls[5 ] : IPRNT2
nastran_int_controls[6 ] : ISCAL
nastran_int_controls[7 ] : ITMAX
nastran_int_controls[8 ] : ITRMOP
nastran_int_controls[9 ] : ITRMAST
nastran_int_controls[10] : JTMAX
nastran_int_controls[11] : JPRINT
nastran_int_controls[12] : JWRITE
nastran_int_controls[13] : METHOD
nastran_int_controls[14] : P1
nastran_int_controls[15] : P2
Real parameters
nastran_real_controls[0 ] : CONV1
nastran_real_controls[1 ] : CONV2
nastran_real_controls[2 ] : CONVDV
nastran_real_controls[3 ] : CONVPR
nastran_real_controls[4 ] : CT
nastran_real_controls[5 ] : CTMIN
nastran_real_controls[6 ] : dabobj
nastran_real_controls[7 ] : delb
nastran_real_controls[8 ] : delobj
nastran_real_controls[9 ] : delp
nastran_real_controls[10] : delx
nastran_real_controls[11] : dobj1
nastran_real_controls[12] : dobj2
nastran_real_controls[13] : dpmin
nastran_real_controls[14] : dx1
nastran_real_controls[15] : dx2
nastran_real_controls[16] : dxmin
nastran_real_controls[17] : gmax
nastran_real_controls[18] : gscal
nastran_real_controls[19] : ptol
nastran_real_controls[20] : Stpscl
For further details please see DOPTRM in the Nastran manual.
Errors
None.