Modeling micro-particles impacts into ballistic gelatine using smoothed particles hydrodynamics method

Investigating high-speed microparticle impact responses into soft tissue is essential to several fields such as medicine and biology with technological applications like transdermal delivery of pharmaceuticals. The understanding of the physical process involved in such a phenomenon is complex and few experimental tools are available to study high-velocity microparticle penetration in soft tissues, generally substituted by simulants like gels in the literature. One way to overcome these issues is to use numerical simulation as an efficient way of investigation, but also include difficulties such as accurate models for materials properties, microscale computation, and mathematical formulations. As the earliest meshless method, Smoothed Particles Hydrodynamics (SPH) has been applied in solid dynamics because of its great potentials in simulating extremely large deformation and perforation of targets by various projectiles. This paper develops an original numerical model based on SPH to study the dynamical phenomena during microscale impact of spheres into ballistic gelatin (BG), a common human tissue surrogate. By simulating a series of particle penetrations into 10 wt% BG initial velocities, the projectile trajectories and penetration depths in gelatin are investigated. The effects of the gelatin's elastic modulus in ballistic impact are also studied. The numerical results show that this numerical model appears to be an promising approach to simulate high-velocity microparticle penetrating ballistic gelatine materials. (C) 2020 Elsevier Ltd. All rights reserved.