The variables for the material update parameters are:
E 
= 
Young’s Modulus 
YS 
= 
Yield Stress of material 
= 
Strength coefficient (power law equation ) 

= 
Prestrain coefficient 

n 
= 
Strainhardening exponent (measures stretch ability/work hardening of material) 
r 
= 
Plastic strain ratio (measures deep draw ability of material) 
Note: Material units must be consistent for all parameters.
The following equations are commonly used to calculate and :
Where:
e = 2.718
TS = tensile strength
YS = yield stress
Some common unit conversions are listed below:

USCU – SI 
SI  USCU 
Length 
1 in = 25.4 mm 
1 mm = 0.03937 in. 
Force 
1 lb = 4.448 N 
1 N = 0.2248 lb 
Stress 
1 Ksi = 6.895 Mpa 
1 Mpa = 0.145 Ksi 
Mass 
1 lbm = 0.4536 kg 
1 kg = 2.205 lbm 
Gravity 