Cooper Eaton; Modified Heckel - Micromeritics DVVA II 4000 Operator's Manual

Appendix B
where
e = void ratio,
e = void ratio at P=0
0
P = applied pressure
a = granulate hardness parameter with units of pressure
b = dimensionless stiffness parameter between 0.3 (spherical grains) and 0.1 (angular
grains)
V = volume of the voids
V
V = volume of the solids
S

Cooper Eaton

The Cooper-Eaton equation is given by:
–
V V
0
----------------- -
–
V V
0
S
where
V = volume at P=0
0
V = volume at P
V = volume of the solid sample
S
P = applied pressure
a a = material characteristic constants
1 2
b b = material characteristic constants
1 2
The terms on the right-hand side of the equation relate to the processes of particle rearrangement
and particle deformation. The constants b
paction due to those processes, while a

Modified Heckel

The Modified Heckel equation is given by:
1

------------ -
ln

1 D –
where
P = applied pressure
D = relative density
B-4
V
v
----- -
V
S
b
 
1
---- -
= exp – + exp
a a
 
1 2
P
1

b
= +
aP c

b
 
2
---- -
–
 
P
and b represent the pressures required to induce com-
1 2
and b indicate the relative magnitude of each process.
2
DVVA II 4000
400-42803-01 (Rev B) - July 2017