基于区块划分并行填充的混凝土细观建模方法及其在弹体超高速侵彻中应用

Based on the need for rapid generation of large and complex finite element model in the mesoscale simulation of high-speed deep penetration, a meso-scale modeling method of concrete based on material property identification, block division and parallel filling is proposed. Different interface transition zone (ITZ) characterization methods are used to verify the characterization ability of the mesoscale modeling method under quasi-static and ultra-high speed penetration conditions. The accelerated modeling method has significant advantages in modeling efficiency and accuracy, which can achieve rapid modeling of large and complex shaped concrete structures and precise proportion allocation of microscopic components. Furthermore, the applicable conditions and the initial judgment criteria of material parameters of different ITZ characterization methods (i. e., ITZ solid element method, non-ITZ method and cohesive contact method) are summarized. The ITZ solid element method has the best prediction effect on penetration depth and crater size in ultra-high speed penetration simulation (the deviation is less than 10%); the cohesive contact method has the relatively worst performance in crater size prediction because it does not introduce strain rate effect and is prone to numerical instability. In addition, the response calculation and morphology characterization of the eroded projectile in the meso-scale simulation are highly consistent with the established nose evolution model for high-speed penetration. The research results can solve the difficulties of modeling the large and complex meso-scale targets in engineering practice, and provide the basis for exploring the meso-scale mechanism of ultra-high speed deep penetration.