Johnson-Holmquist model in Abaqus

Hello,

I am trying to model SiC as a ceramic material using the Johnson-Holmquist model. 

As in Abaqus this material model is not available using GUI I have to specify in the input file as shown in example 2.1.18 High velocity impact of ceramic target. 

In this example silicon carbide material has been used with following parameters

rho0 = 3.215e-9

G = 193000.

A = 0.96

N = 0.65

B = 0.35

M = 1.0

C = 0.009

edot0 = 1.0

T = 750

sigIMax = 12200

sigFMax = 1300

HEL = 11700

PHEL = 5130

beta = 1.0

D1 = 0.48

D2 = 0.48

efMax = 1.2 

efMin = 0.0

K1 = 220000

K2 = 361000

K3 = 0.0

FS = 0.2

lDamage = 0

*Material, name=abq_jh2_siliconcarbide

when I use the above parameters for a SiC slab being impacted using a bullet. The bullet appears to pierce through the silicon carbide layers. However only a few elements in the silicon carbide top layer appear to be damaged (status = 0 and removed from the model). The rest of the affected elements  that allow the bullet to pass remain intact with status variable showing value 1.

Is this because of the parameter FS - 0.2

or IDamage = 0

I have used General Contact (all with self) for the whole model with interaction normal hard contact.

Any suggestions is highly appreciated.

Thanks

Shouvik