Study on the formation of micro-scale shaped charge jet based on diameter effect

Shaped charge jets (SCJ), characterized by high power, favorable directionality, and broad platform compatibility, are well suited for low-overload miniature weapon platforms. At the micro-scale, however, charge diameter introduces pronounced size effects that are not captured by classical shaped-charge theory, leading to a systematic overestimation of jet velocity. This study aims to address the limitations of conventional theory, particularly the inadequate prediction of jet velocity for micro-scale charges. Theoretical analyses and detonation experiments are first conducted to verify the existence of a size effect, with the experimental results confirming a marked reduction in detonation velocity at reduced charge diameters. Building on these findings and integrating classical jet-formation theory, the formulations for liner collapse velocity and jet velocity are refined. A pulsed X-ray test employing a 10 mm diameter shaped charge was performed to validate the proposed model. The measured jet tip velocity was [3077.0 m/s], while the conventional model predicted [3921.5 m/s] and the modified model predicted [3189.6 m/s]. The modified model exhibits strong agreement with the experimental data, reducing the prediction error relative to the conventional theory by approximately 20%. These results provide essential guidance for the design and optimization of micro-scale shaped charges.