Week - 1 - Consistency of Units

Aim: To convert the SI unit system quantites to the all different types of parameters and to tabulate the unit system for all the different types of unit systems mentioned.

Objective:To convert the multiple quantity values to different unit systems and also create a table such that there won't be any problem while using LS-Dyna as it doesn't has a default unit system.

Procedure:

Given SI quantity values:

Mass =1Kg

Length=1m

Time=1s

Force=1N

Stress=1Pa

Energy=1Nm

Density=1Kg/m^3

Young's Modulus=210GPa

Velocity=56.33KMPH

Gravity=9.8m/s^2

Conversion of SI Unit to gm mm ms:

Mass 1KG= 1000gm

Length 1M= 1000mm

Times 1S=1000ms

Force 1N

Force = Mass* Acceleration

          = 1KG*1m/s^2

          =(1000gm*1000mm)/(1000ms)^2

          1(gm*mm)/ms^2

Stress 1Pa=10^-6gm/mm*ms^2

1Pa=1N/m^2

{1(gm*mm/ms^2)}/(1000mm^2)

1*10^-6gm/mm*ms^2

Energy1Nm=10^3

1N* 1m

{1gm* mm/ms^2}*1000mm

1000gm*mm^2/ms^2

10^3gm mm^2/ms^2

10^3

Density 1Kg/m3=10^-6Kg/cm^3

1000gm/(1000mm)^3

1gm/1000000mm^3

10^-6gm/mm^3

Young's Modulus 210 GPa=210*10

1Pa=10^-3gm/mm*ms

1GPa=10*10gm/mm ms

210GPa=210*10gm/mm ms

Conversion factor=10

velocty 56.33KMPH

1Km=1000000mm=10mm

1hr=60*60*1000

=3600000

=36*10ms

1kmph=(10)/(36*10)

=0.277mm/ms

=56.33kmph

=56.33*0.277mm/ms

=15.60mm/ms

Gravity 9.8m/s^2=0.1560cm/ms

1m/s^2=1000mm/(1000ms^2)

=10^-3mm/ms^2

9.8m/s^2=9.8*100^-3mm/ms^2

Conversion factor=10^-3mm/ms^2

Conversion Factor=10^-3mm/ms^2

Thus LS Dyna can be user friendly as if the conversions are known.