Week - 1 - Consistency of Units

Aim:

To write the conversion of the unit that requires in the LS Dyna system.

Objective:

Need to find the conversion factor for following system as given below:

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

To write down the measurement in the above different system of units and respectively need to mention the conversion factor.

PROCEDURE:

The calculation is done for the measurements for 1 SI unit system and the same process is considered for all others

	SI Unit (kg, m, s)	Conversion unit (gm, mm, ms)	Conversion factor
Mass	1	1000	1000
Length	1	1000	1000
Time	1	1000	1000

Derived quantities are calculated they cannot be measured or assumed directly.

Force 1N

Force = mass * acceleration

1N = kg x m/s^2

1N = 1000g * 1000 mm/1000 ms^2

1N = 10^6/10^-6 (g x mm/ms^2)

1N = 1 (g x mm/ms^2)

(Conversion factor = 1)

Stress 1Pa

1 Pa = 1 N/m^2 = [1 kg x (1 m/s^2)] / m^2

(Conversion factor = 10^-6)

(Conversion factor = 10^3)

(Conversion factor = 10^-6)

(Conversion factor = 10^3)

(Conversion factor = 1)

(Conversion factor = 10^-3)

Conversion for other SI units

Discussion and Learning Outcomes:

• This challenge is got knowledge about SI unit and conversion unit in LS Dyna.
• LS Dyna doesn't have a default system of units. User needs to input material properties and physical dimensions according a consistent system of units as per their choice.