OBJECTIVES

 Identify different penetration phases and associated damage mechanisms for thick-section composite materials
 Use LS-DYNA simulations to model penetration and perforation of composites utilizing the progressive composite damage model MAT162.
 Investigate penetration damage mechanisms below and above the ballistic limit by observing the cross-section of the composite laminate at different times
 Develop theoretical models for different phases of penetration

PENETRATION OR P-PHASE

 Transverse matrix damage and delamination is observed around the depth of penetration cavity
 No matrix cracking or delamination damage under the projectile
 No visible dynamic deflection of the back face lamina

TRANSITION OR T-PHASE

 Transverse matrix damage and delamination forms damage cone
 Composite under and surrounding the projectile undergoes dynamic deformation

PERFORATION OR F-PHASE

 The projectile and composite in contact move together with same particle velocity
 Back face dynamic deflection reaches maximum at end of F-phase

RETRACTION OR R-PHASE

 Particle velocity of last sub-laminate at the peak deflection becomes zero
 Particle velocity reverses its direction of motion
 Last sub-laminate and remaining laminates retract back

DEFORMATION DYNAMICS: P-T-F-PHASES

SUMMARY

 Four penetration phases have been identified for finite thickness thick-section composites
 Deformation mechanisms of each penetration phase have been identified which can be used to develop theoretical models of these penetration phases

ACKNOWLEDGEMENTS

 This work is supported by the ARL-CMR and ARL-CART Programs