DVCON_SIZING


ID_NAME	= `<name_of_dvcon_sizing>`	Name of the `DVCON_SIZING` definition.
EL_GROUP	= `<name_of_element_group>`	Name of an element group already defined with which `DVCON_SIZING` should react.
CHECK_TYPE
	= FROZEN	All elements of the element group `<name_of_element_group>` do not undergo any changes during optimization.
	= THICKNESS_BOUNDS	Upper and lower bounds (relative or absolute) for shell thickness.
	= CLUSTER_GROUPS	Clustering of shell elements with the same shell thickness. Several `EL_GROUP` items can be defined with this `CHECK_TYPE`.
	= MIN_CLUSTER_WIDTH	Minimum width filter (definition of the minimum width of structures of same shell thickness created by sizing).
	= LINK_SIZING	Definition of symmetry and link conditions.
	= DISCRETE	Restrict design variables to be discrete by the end of optimization. A list with discrete values should be provided by the user.

Items for CHECK_TYPE = THICKNESS_BOUNDS


MAGNITUDE	= REL = ABS	Relative (relative x start value) or absolute value for choice of shell thickness.
LOWER_BOUND	=`<lower_bound>`	Lower bound for shell thickness. For `MAGNITUDE=REL` the lowest value for shell thickness is `lower_bound x initial_shell_thickness`.
UPPER_BOUND	=`<upper_bound>`	Upper bound for shell thickness. For `MAGNITUDE=REL` the highest value for shell thickness is `upper_bound x initial_shell_thickness`.

Items for CHECK_TYPE = CLUSTER_GROUPS


EL_GROUP	= `<name_of_element_group>`	Can be applied several times to assign multiple groups.

Items for CHECK_TYPE = MIN_CLUSTER_WIDTH


WIDTH	= `<width>`	Minimum width of the structure.

Items for CHECK_TYPE = LINK_SIZING


CHECK_LINK	= `<name_of_link_sizing>`	Reference of the corresponding `LINK_SIZING` definition.
RADIUS	= `<radius>`	Radius value: should be about 50% of the average element edge length, if specified.

Items for CHECK_TYPE = DISCRETE


DISCR_LIST_FILE	= `<file_name.csv>`	Name of the file containing the discrete range. This is a mandatory parameter. Only one file is allowed inside the `DISCRETE` block. This file should contain only one labeled column with arbitrary length.
DISCR_CYCLE	= `<integer_value>`	Initial cycles to be allowed before constraining. Optional, set enough cycles to achieve partial convergence. (9-15 is a good choice.)
DISCR_INTERVAL	= `<integer_value>`	Cycles between the fixing of DVs. Optional, set enough cycles to allow the solution to converge again. (3-10 is a good choice.)
DISCR_FRACTION	= `<real_value>`	Maximum fraction of the DVs to be fixed in one iteration. Optional, can be set in range 0-1. (0.1-0.3 is a good choice.)
DISCR_CHANGE	= `<real_value>`	The maximum allowed change in the individual DVs over two iterations. DVs with changes below the threshold are considered to be converged and remain fixed for the rest of the optimization. The item is optional. Set to small values (0.001, 0.1) for accurate results and to very large values (>10) for fast and guaranteed convergence. However, for small values, the number of iterations cannot be estimated.

Remarks

The element group that should be restricted must be a subset of the referenced element group of DV_SIZING; all elements that should be restricted must lie in this design area.
For CHECK_TYPE = THICKNESS_BOUNDS, relative values (positive real values) can be used to create lower and upper bounds based on the initial shell thickness. In this case, the shell thicknesses can vary between <lower_bound x initial_thickness> and <upper_bound x initial_thickness>.
The combination of a minimum member size constraint and a maximum member size constraint is not allowed. Use the MIN_WIDTH parameter in the maximum member size constraint instead.

Examples

DVCON_SIZING
 ID_NAME     = my_dvcon_sizing_01
 EL_GROUP    = my_element_group
 CHECK_TYPE  = THICKNESS_BOUNDS
 MAGNITUDE   = REL
 LOWER_BOUND = 0.8
 UPPER_BOUND = 1.2
END_

DVCON_SIZING
 ID_NAME    = my_dvcon_sizing_02
 EL_GROUP   = my_element_group1
 EL_GROUP   = my_element_group2
 CHECK_TYPE = CLUSTER_GROUPS
END_