Curve UNITs
Curve UNITs
From version 9.4 onwards a T/HIS curve file can also contain information on the Unit system and the X and Y axis units.
A unit system is defined by a line starting with $ UNIT SYSTEM and will take the format
$ UNIT SYSTEM : system name
The following unit systems names can be specified by using either the full name or just " Un ."
U1: m, kg, s (SI)
U2: mm, t, s
U3: mm, kg, ms
U4: mm, g, ms
U5: ft, slug, s
U6: m, t, s
The X and Y axis units are defined by a line starting with either $ X AXIS UNIT or $ Y AXIS UNIT and take one of the 2 following formats
$ X AXIS UNIT : unit name
$ X AXIS UNIT : mass,length,time,angle,temperature,current
For the 1st format thefollowing predefined unit names are available.
|
Time
|
Rotation
|
Momentum
|
Energy
Den
|
|
Energy
|
Rot Vel
|
Density
|
Mass Flow
|
|
Work
|
Rot Accel
|
Stress
|
Frequency
|
|
Temperature
|
Length
|
Strain
|
Power
|
|
Displacement
|
Area
|
Force
|
Thermal
Flux
|
|
Velocity
|
Volume
|
Moment
|
Force width
|
|
Accel
|
Mass
|
Pressure
|
Moment
width
|
If the axis units are NOT one of these predefined units then the second input format can be used to define the unit in terms of it's basic properties. The values for mass, length, time, angle, temperature and current should be the powers that are used to describe the unit in terms of it's fundamental dimensions.
Some examples of common units defined using this method are shown below.
| Unit |
Mass
|
Length
|
Time
|
Angle
|
Temperature
|
Current
|
| Time |
0.0
|
0.0
|
1.0
|
0.0
|
0.0
|
0.0
|
| Displacement |
0.0
|
1.0
|
0.0
|
0.0
|
0.0
|
0.0
|
| Velocity |
0.0
|
1.0
|
-1.0
|
0.0
|
0.0
|
0.0
|
| Acceleration |
0.0
|
1.0
|
-2.0
|
0.0
|
0.0
|
0.0
|
| Stress |
-1.0
|
1.0
|
-2.0
|
0.0
|
0.0
|
0.0
|