A numerical simulation method of natural fragment formation and injury to human thorax.

Objective: Fragment injury is a type of blast injury that is becoming more and more common in military campaigns and terrorist attacks. Numerical simulation methods investigating the formation of natural fragments and injuries to biological targets are expected to be developed.

Methods: A cylindrical warhead model was established and the formation process of natural fragments was simulated using the approach of tied nodes with failure through the explicit finite element (FE) software of LS-DYNA.

Characterizing Hypervelocity Impact (HVI)-Induced Pitting Damage Using Active Guided Ultrasonic Waves: From Linear to Nonlinear.

Hypervelocity impact (HVI), ubiquitous in low Earth orbit with an impacting velocity in excess of 1 km/s, poses an immense threat to the safety of orbiting spacecraft. Upon penetration of the outer shielding layer of a typical two-layer shielding system, the shattered projectile, together with the jetted materials of the outer shielding material, subsequently impinge the inner shielding layer, to which pitting damage is introduced. The pitting damage includes numerous craters and cracks disorderedly scattered over a wide region.