Week - 1 - Consistency of Units
Week - 1 - Consistency of Units
Aim : To convert the given measurement values to different unit systems.
Objective : Different industries use different system of units as per their convenience. The units for the basic measurement quantities, mass distance and time - dictate how the other derived quantities will be expressed. For example, automotive industries use kg,mm,ms as their standard unit system. Construction industries are likely to use tonne,m,s as their unit system. Similarly, PCB simulation in electronic industry uses gm, micrometer,ms as their system of units.
- LS-DYNA doesn't have a default system of units. User needs to input material properties and physical dimensions according to a consistent system of units as per their choice. This warrants that to use LS-DYNA in different circumstances, users has to be conversant with converting quantities from one system of units to another.
- Here's an example: Young's Modulus of steel is 210GPa which is input as 210e+9 in LS-DYNA as per SI unit system. However, if you use kg/mm/ms unit system, the input quantity will be 210. Thus, the conversion factor is 10^-9.
Value of the following measurements are given as follows :
- MASS 1kg
- LENGTH 1m
- TIME 1s
- FORCE 1N
- STRESS 1Pa
- ENERGY 1Nm
- DENSITY 1Kg/m3
- YOUNG'S Modulus 210GPa
- Velocity 56.33KMPH
- GRAVITY 9.8m/s2
Now, here are a few system of units :
- Kg cm ms
- Kg cm s
- gm mm ms
- kg m s
- g cm s
- g cm us
- g mm s
- ton mm s
- slug ft s
- kg mm s
- g cm ms
- kg mm ms
1. Conversion to (g, mm, ms)
2. Conversion to (kg, cm, ms)
3. Conversion to (kg, cm, s)
4. Conversion to (g, cm, s)
5. Conversion to (kg, m, s)
6. Conversion to (g, cm, μs)
7. Conversion to (g, mm, s)
8. Conversion to (Ton, mm, s)
9. Conversion to (Slug, ft, s)
10. Conversion to (kg, mm, s)
11. Conversion to (g, cm, ms)
12. Conversion to (kg, mm, ms)
Conclusion:
The values are converted into respected unit system, since Ls Dyna doesn't have a specific unit system the above assignment will be useful in deploying the units while performing simulation.