user_manual:sesamx:functions_description:create_units

3.5.2. SET-UNITS function

optional unique

Description

SesamX embeds predefined physical quantities, each of them carries a unit that you are free to define. On input, each SesamX keyword is related to a physical quantity which provides the unit used to understand the numerical data. And this manual gives the physical quantity related to each keyword next to its description, as explained in the introduction.

For instance, the POINT keyword of the ADD-MESH function is related to the LENGTH quantity. And using the SET-UNITS function you can define the unit carried by this LENGTH quantity.

Similarly, each output data is related to a physical quantity that provides the unit used to express the requested data.

The SET-UNITS function is therefore used to define the unit associated with each predefined physical quantity. SesamX expects you to provide the name of the units (for instance 'MM') as well as the coefficient to the standard unit system.

Until the first call to the SET-UNITS function, SesamX assumes the following default units values.

Physical quantity Unit name Coef to SI
LENGTH M 1.
TRANSLATION MM 1.E-3
ROTATION DEG 1.7453E-2
MODULUS GPA 1.E9
DENSITY KG/M3 1.
THICKNESS MM 1.E-3
AREA MM2 1.E-6
STRESS MPA 1.E6
STRAIN % 1.E-2
TRANS-STIFF N/M 1.
ROT-STIFF NM/RAD 1.
FORCE N 1.
MOMENT NM 1.
G-INERTIA MM4 1.E-12
TIME S 1.

The units that you define in a SesamX input file are effective only while running this input file. The information is not stored inside the SesamX database.

For convenience we are talking here about the standard unit system as a reference for the units coefficients that you define. Nevertheless, you are free to define the units coefficients with reference to your preferred unit system. Everything will work fine as long as your unit system is consistent. For instance taking the ton, mm, s unit system as a reference, the coefficient for a stress expressed in MPa is 1.

LENGTH branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES M
Name of the unit
COEF FLOAT 1 YES 1.
Coefficient to the standard unit system

TRANSLATION branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES MM
Name of the unit
COEF FLOAT 1 YES 1.E-3
Coefficient to the standard unit system

ROTATION branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES DEG
Name of the unit
COEF FLOAT 1 YES 1.7453E-2
Coefficient to the standard unit system

MODULUS branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES GPA
Name of the unit
COEF FLOAT 1 YES 1.E9
Coefficient to the standard unit system

DENSITY branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES KG/M3
Name of the unit
COEF FLOAT 1 YES 1.
Coefficient to the standard unit system

THICKNESS branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES MM
Name of the unit
COEF FLOAT 1 YES 1.E-3
Coefficient to the standard unit system

AREA branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES MM2
Name of the unit
COEF FLOAT 1 YES 1.E-6
Coefficient to the standard unit system

STRESS branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES MPA
Name of the unit
COEF FLOAT 1 YES 1.E6
Coefficient to the standard unit system

STRAIN branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES %
Name of the unit
COEF FLOAT 1 YES 1.E-2
Coefficient to the standard unit system

TRANS-STIFF branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES N/M
Name of the unit
COEF FLOAT 1 YES 1.
Coefficient to the standard unit system

ROT-STIFF branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES NM/RAD
Name of the unit
COEF FLOAT 1 YES 1.
Coefficient to the standard unit system

FORCE branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES N
Name of the unit
COEF FLOAT 1 YES 1.
Coefficient to the standard unit system

MOMENT branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES NM
Name of the unit
COEF FLOAT 1 YES 1.
Coefficient to the standard unit system

G-INERTIA branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES MM4
Name of the unit
COEF FLOAT 1 YES 1.E-12
Coefficient to the standard unit system

TIME branch

optional default values unique

Keywords

Name Data Type Data number Optional Default value Physical quantity
NAME STRING 1 YES S
Name of the unit
COEF FLOAT 1 YES 1.
Coefficient to the standard unit system

Examples

SET-UNITS
  LENGTH
    NAME: MM
    COEF: 1E-3
  THICKNESS
    NAME: INCH
    COEF: 2.5E-2
  ROTATION
    NAME: RAD
    COEF: 1.

See also

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References

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  • user_manual/sesamx/functions_description/create_units.txt
  • Last modified: 2023/05/30 21:47
  • by Ali Baba