Numerical Modeling of Shockwave Treatment of Knee Joint

Arthritis is a degenerative disease that primarily affects the cartilage and meniscus of the knee joint. External acoustic stimulation is used to treat this disease. This article presents a numerical model of the knee joint aimed at the computer-aided study of the regenerative effects of shockwave treatment. The presented model was verified and validated. A numerical analysis of the conditions for the regeneration of the tissues of the knee joint under shockwave action was conducted. The results allow us to conclude that to obtain the conditions required for the regeneration of cartilage tissues and meniscus (compressive stresses above the threshold value of 0.15 MPa to start the process of chondrogenesis; distortional strains above the threshold value of 0.05% characterized by the beginning of the differentiation of the tissues in large volumes; fluid pressure corresponding to the optimal level of 68 kPa to transfer tissue cells in large volumes), the energy flux density of therapeutic shockwave loading should exceed 0.3 mJ/mm2.

Melting and density of MgSiO3 determined by shock compression of bridgmanite to 1254GPa

The essential data for interior and thermal evolution models of the Earth and super-Earths are the density and melting of mantle silicate under extreme conditions. Here, we report an unprecedently high melting temperature of MgSiO3 at 500 GPa by direct shockwave loading of pre-synthesized dense MgSiO3 (bridgmanite) using the Z Pulsed Power Facility. We also present the first high-precision density data of crystalline MgSiO3 to 422 GPa and 7200 K and of silicate melt to 1254 GPa. The experimental density measurements support our density functional theory based molecular dynamics calculations, providing benchmarks for theoretical calculations under extreme conditions. The excellent agreement between experiment and theory provides a reliable reference density profile for super-Earth mantles. Furthermore, the observed upper bound of melting temperature, 9430 K at 500 GPa, provides a critical constraint on the accretion energy required to melt the mantle and the prospect of driving a dynamo in massive rocky planets.

Structure Analysis of Marine Pipes under the Effect of Water Explosion Force (Wave)

Underwater explosion is a subject that has been paid attention to by many researchers. In this study the underwater explosion phenomena under shockwave loading is explored by numerical method. For this purpose, by modeling a marine pipe buried in the water by ABAQUS software, the effect of the shock wave and the damages were assessed. Then using the laboratorial results, the fluid-structure interaction and shock wave loading and its results were analysed. Finally, it was concluded from numerical modeling that the highest levels of strain on the pipe buried in the water under underwater explosion and shock wave loading occur in the ending parts of the pipe in both sides and away from explosion field.

Calculation of Shock Adiabats for Materials Undergoes a Phase Transition

We propose a model that allows a single velocity and temperature approximation, and assuming the same pressure for all phases, to calculate the behavior of porous powder mixtures during shockwave loading taking into account the phase transition. Numerical results are compared with available experimental results of different authors to solid and porous media(shock adiabat, double compression shock waves). It is shown that the calculation gives good agreement with experiment for graphite and titanium