DEF_TYPE = OPER

VAR_OPER

Operator linking the variables VAR_A to VAR_D.

Operators with 2 operands:

= SUB

Subtraction.

A - B

= SUB_ABS

Absolute value of the subtraction.

| A - B |

= ADD_ABS

Addition of absolute values.

This operator is only allowed in context of sensitivity based topology optimization.

$\sqrt{A^2+B^2}$

Operators with up to 2500 operands:

= COMBINE

Weighted sum of up to 10 variables.

Var1*w1 + Var2*w2 +...

= KSO

Kreisselmaier-Steinhauser operator. This operator is only allowed in context of sensitivity-based topology and sizing optimization. It can be used only for combination of frequency (DYN_FREQ) design responses.

$-\frac{1}{k}ln\left(\sum _j{e}^{-k{f}_j}\right)$

Specifying the operands for SUB and SUB_ABS with their ID_NAME:

VAR_A

= <var_id_a>

VAR_B

= <var_id_b>

Specification of operands for COMBINE with their ID_NAME (can be specified several times):

VARIABLE

= <var_id>,<weight>

Only displacements and rotations, modal eigenfrequencies or reaction forces and internal forces are allowed.

if the weight parameter is not specified it is assumed to be 1.

Specification of operands for KSO with their ID_NAME (can be specified several times):

VARIABLE

= <var_id>

Only frequency (DYN_FREQ) design responses are allowed.

VAR_OPER

Operator linking the variables VAR_A to VAR_D.

Operators with 2 to 4 operands:

= ADD

Addition.

A+B+C+D

= MULT

Multiplication.

A*B*C*D

= MIN

Minimum.

min(A,B,C,D)

= MAX

Maximum.

max(A,B,C,D)

Operators with 2 operands:

= SUB

Subtraction.

A - B

= DIV

Division.

A / B

Operators with 1 operand:

= ABS

Absolute value.

abs(A)

= SIN

Sinus.

sin(A)

= COS

Cosinus.

cos(A)

= CUT_OFF

Cutoff operator to remove peaks

(parameters are specified with additional settings).

max(<CUT_OFF_LOW>, min(A,<CUT_OFF_HIGH>))

= TAN

Tangens.

tan(A)

= LOG

Common logarithm.

log(A)

= EXP

Exponential function.

exp(A)

= FILTER

Filter function for vectors used as terms for the controller-based algorithms (parameters are specified with additional settings).

filter(A)

= LN

Nat. logarithm.

ln(A)

= NORM

Norm for vectors (maximum norm) used as terms for the controller-based algorithms.

$\Vert A\Vert$

= NORM_FIRST

Norm for vectors (maximum norm) used as terms for the controller-based algorithms, based on the value in first iteration .

$\Vert A\Vert$

= NPOWER

N-th power to A (parameter is specified with EXPONENT item).

$A^n$

= NROOT

N-th root (parameter is specified with EXPONENT item).

$\sqrt[n]{A}$

= SQRT

Square root.

sqrt(A)

= INT

Integer.

int(A)

= NINT

Nearest integer number.

nint(A)

= SIGN

Sign function.

sign(A)

= DELTA_1

Difference between 2 iterations A(i) - A(i-1).

= DELTA_2

Difference between 2 iterations A(i) - A(i-2).

= DELTA_3

Difference between 2 iterations A(i) - A(i-3).

= DELTA_4

Difference between 2 iterations A(i) - A(i-4).

= DELTA_5

Difference between 2 iterations A(i) - A(i-5).

= DELTA_6

Difference between 2 iterations A(i) - A(i-6).

Operators with up to 10 operands:

Operands defined by item VARIABLE.

= COMBINE

Weighted addition.

w1*VAR1 + w2*VAR2 ...

Specifying the operands with their ID_NAME:

VAR_A

= <var_id_a>

VAR_B

= <var_id_b>

VAR_C

= <var_id_c>

VAR_D

= <var_id_d>

RADIUS

= <radius value>

Real value.

The radius defines the maximum distance for influencing neighbour nodes.

EXPONENT

= <exponent value>

= 1.0

Real value.

SIGMA

= <value>

= 0.2

Real value.

Sigma defines the reduction of the radius depending on the surface bending.

Additional settings for VAR_OPER = CUT_OFF:

CUT_OFF_LOW

= <value>

Real value.

Lower bound of the vector value. All values under this value will be treated as zero.

CUT_OFF_HIGH

= <value>

Real value.

Upper bound of the vector value. All values higher than this value will be set to the cut off value.

Operands for VAR_OPER = COMBINE:

VARIABLE

= <var_id_1>, <weight1>

= <var_id_1>, <1>

ID_NAME of variable var1 with weight factor w1 for combination.

Up to 10 different variables can be specified.