Week - 1 - Consistency of Units
UNIT CONVERSIONS
AIM:
To convert the given measurements in to the specified system of units
PROCEDURE:
The units in the SI system will be in Meter (m), Kilogram (Kg), Second (s), Newton (N). So the youngs modulus (E) of 210 GPa can be written as;
210GPa = 210e+9 Pa = 210e+9 N/m2
Since we require the E in kg/mm/ms unit system.
210e+9 N/m2 = 210e+9 x 1e-6 n/mm2
1N/m2 = 1N/(1e+3mm)2 , 1m = 1e+3 mm
= 210e+3 N/mm2
1N/m2 = 1e-6 N/mm2
1N = 1kg x m/s2
= 1Kg x 1e+3 mm/(1e+3ms)2
= 1Kg x 1e+3mm/ 1e+6ms2
= 1Kg x mm/ 1e+3ms2
= 1e-3 Kg x mm/ ms2 = 1e-3 N
while substituting the e+3 and e-3 cancels and ends up with 210
Thus we can enter 210Gpa as 210 in LS-DYNA as per Kg/mm/ms unit system and if we multiply with 1e-9 then it wll cancels the powers in SI unit systen by leaving the magnitude as per the required unit system so its considered as the conversion factor.
Units conversion:
| System of Units | 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 |
| Kg cm ms | 1kg | 100cm | 1000ms | 1e-4 kg cm/ms2 | 1e-8 kg/ cm. ms2 | 1e-2 kg cm2/ms2 | 1+e-6 kg/cm3 | 2100 Kg/cm ms2 | 1.5647 cm/ms | 9.8e-4 cm/ms2 |
| Kg cm s | 1kg | 100cm | 1s | 1e+2 kg cm/s2 | 1e-2 kg/cm.s2 | 1e+4 kg cm2/s2 | 1+e-6 kg/cm3 | 210e+7 Kg/ cm s2 | 15.647e+2 cm/s | 9.8e+2 cm/s2 |
| gm mm ms | 1000gm | 1000mm | 1000ms | 1 gm mm/ms2 | 1e-6 gm/mm ms2 | 1e+3 mm2/ms2 | 1+e-6 gm/mm3 | 210e+3 gm /mm ms2 | 15.647 mm/ms | 9.8e-3 mm/ms2 |
| kg m s | 1kg | 1m | 1s | 1N | Pa (N/m2) | 1 kg m2/s2 (J) | 1 kg/m3 | 210e+9 Pa | 15.647 m/s | 9.8 m/s2 |
| g cm s | 1000g | 100cm | 1s | 1e+5 gm cm/s2 | 1e+1 gm/cm s2 | 1e+7 gm cm2/s2 | 1e-3 g/cm3 | 210e+10 g/ cm s2 | 15.647e+2 cm/s | 9.8e+2 cm/s2 |
| g cm μs | 1000g | 100cm | 1e+6μs | 1e-7 gm cm/μs2 | 1e-11 gm/cm μs2 | 1e-5 gm cm2/μs2 | 1e-3 g/cm3 | 210e-2 g/cm μs2 | 15.647e-4 cm/μs | 9.8e-10 cm/μs2 |
| g mm s | 1000g | 1000mm | 1s | 1e+6 gm mm/s2 | 1 g/mm s2 | 1e+9 gm mm2/s2 | 1+e-6 g/mm3 | 210e+9 g/mm s2 | 15.647e+3 mm/s | 9.8e+3 mm/s2 |
| ton mm s | 1e-3 ton | 1000mm | 1s | 1 ton mm/s2 | 1e-6 ton/mm s2 | 1e+3 ton mm2/s2 | 1e-12 ton/mm3 | 210e+3 ton /mm s2 | 15.647e+3 mm/s | 9.8e+3 mm/s2 |
| slug ft s | 0.068slug | 3.28ft | 1s | 0.223 slug ft/s2 | 0.02 slug/ft s2 | 0.731slug ft2/s2 | 1.9e-3 slug/ft3 | 4.3536e+9 slug/ ft s2 | 51.3228 ft/s | 32.144 ft/s2 |
| kg mm s | 1kg | 1000mm | 1s | 1e+3 kg mm/s2 | 1e-3 kg/mm s2 | 1e+6 kg mm2/s2 | 1e-9 kg/mm3 | 210e+6 Kg/mm s2 | 15.647e+3 mm/s | 9.8e+3 mm/s2 |
| g cm ms | 1000g | 100cm | 1000ms | 1e-1 g mm/ms2 | 1e-5 gm/cm ms2 | 1e+1 gm cm2/ms2 | 1e-3 g/cm3 | 210e+4 g/sm ms2 | 1.5647 cm/ms | 9.8e-4 cm/ms2 |
| kg mm ms | 1kg | 1000mm | 1000ms | 1e-3 kg mm/ms2 | 1e-9 kg/mm ms2 | 1kg mm2/ms2 | 1e-9 kg/mm3 | 210 kg/mm ms2 | 15.647 mm/ms | 9.8e-3 mm/ms2 |
conversion factors:
| System of Units | MASS 1kg | LENGTH 1m | TIME 1s | FORCE 1N | STRESS 1Pa | ENERGY 1Nm | DENSITY 1Kg/m3 | YOUNG'S Modulus 210GPa | Velocity 56 | GRAVITY |
| Kg cm ms | 1 | 100 | 100 | 1e-4 | 1e-8 | 1e-2 | 1+e-6 | 1e-8 | 0.0277 | 1e-4 |
| Kg cm s | 1 | 100 | 1 | 1e+2 | 1e-2 | 1e+4 | 1+e-6 | 1e-2 | 27.77 | 1e+2 |
| gm mm ms | 1000 | 1000 | 1000 | 1 | 1e-6 | 1e+3 | 1+e-6 | 1e-6 | 0.277 | 1e-3 |
| kg m s | 1 | 1 | 1 | 1 | 1 | 1 kg | 1 | 1 | 0.277 | 1 |
| g cm s | 1000 | 100 | 1 | 1e+5 | 1e+1 | 1e+7 | 1e-3 | 1e+1 | 27.77 | 1e+2 |
| g cm μs | 1000g | 100 | 1e+6 | 1e-7 | 1e-11 | 1e-5 | 1e-3 | 1e-11 | 2.77e-5 | 1e-10 |
| g mm s | 1000 | 1000 | 1s | 1e+6 | 1 | 1e+9 | 1+e-6 | 1 | 277.77 | 1e+3 |
| ton mm s | 1e-3 | 1000 | 1s | 1 | 1e-6 | 1e+3 | 1e-12 | 1e-6 | 277.77 | 1e+3 |
| slug ft s | 0.068 | 3.28 | 1 | 0.223 | 0.02 | 0.731 | 1.92e-3 | 0.0207 | 0.9111 | 3.28 |
| kg mm s | 1 | 1000 | 1 | 1e+3 | 1e-3 | 1e+6 | 1e-9 | 1e-3 | 277.77 | 1e+3 |
| g cm ms | 1000 | 100 | 1000 | 1e-1 | 1e-5 | 1e+1 | 1e-3 | 1e-5 | 0.0277 | 1e-4 |
| kg mm ms | 1 | 1000 | 1000 | 1e-3 | 1e-9 | 1 | 1e-9 | 1e-9 | 0.277 | 1e-3 |
Calculations:
SI unit to gm/mm/ms.
1Kg = 1e+3 gm
1m = 1e+3 mm
1s = 1e+3 ms.
FORCE 1N
= 1 Kg x m/s2
= 1e+3 gm x 1e+3 mm/ (1e+3ms)2
= [1e+3 x 1e+3 x 1e-6] gm.mm/ms2
= 1 gm.mm/ms2
STRESS 1Pa
= 1N/m2
= 1N/ (1e+3mm)2
= 1e-6 gm/ ms2.mm
ENERGY 1Nm
= 1e+3 gm mm2/ms2
DENSITY 1kg/m3
= 1e+3 gm/1e+9 mm3
= 1e-6 gm/mm3
YOUNG'S Modulus 210GPa
= 210e+9 N/m2
= 210e+9 N/1e+6mm2
= 210e+3 gm /mm ms2
Velocity 56.33KMPH
= 56.33 x 1e+6 mm /3600 x 1e+3 ms
= 15.647 mm/ms
CONCLUSION:
The given measurements were converted in to different unit systems as per the specification and the detailed calculation is done in order to convert the units.