Theoretical and Experimental Studies on Pyroshock Attenuation via Periodic Rods

Pyrotechnic releasing devices have been widely used in aerospace missions to separate subsystems from spacecraft. High-frequency transient pyroshock induced by pyrotechnic release devices may cause severe damage to electronic devices and involved systems. To mitigate the pyroshock, phononic crystals, as new artificial constructions with novel properties, are introduced for the first time. In the present study, the pyroshock propagation analysis in periodic composite rods consisting of two different materials is conducted both theoretically and experimentally by considering various geometry parameters. The band gaps, attenuation level, and dynamic responses of periodic rods are investigated by the differential quadrature method, and the simulation results are validated by finite element analysis. Using the established theoretical model and laser-generated shock experimental setups, the effect of geometry on wave propagation behaviors, dynamic responses, shock response spectrums, and pyroshock attenuation in periodic rods are investigated. The experimental and numerical results are in good agreement, demonstrating that effective shock attenuation may be achieved through periodic rods. The corresponding attenuation bands, attenuation trends, and turning points of shock response spectrums can be controlled by designing the geometry of periodic rods. The pyroshock attenuation effects in periodic rods can be predicted quantitatively by wave propagation analysis.