MATERIAL RESPONSE AT HYPERVELOCITY IMPACT CONDITIONS USING LASER-INDUCED SHOCK-WAVES

Dynamic fracture at hypervelocity impact conditions was investigated i n different materials using short pulsed laser induced shock waves. Al l stages of damage evolution were identified for one dimensional or sp herical shock wave impact geometry. A new experimental method is prese nted to estimate the shock pressure decay in materials. In the theoret ical section we obtain the damage induced in the target, as follows: T he shock wave is modeled by an expanding stress front, which creates m icro-damage in the laser impacted layer and extrudes a bulge at the fa r surface. The calculated bulge geometry compares well with that obser ved by us for metal-adhesive-metal sandwiches. The micro-defects coale sce into macro- damage or fracture by a mechanism which is described b y percolation theory.