基于FE重构方法的冲击破碎仿真  

Combination of FE and SPH method for impact fragmentation

作　　者：张晓天[1] 贾光辉[1] 黄海[1] 

机构地区：[1]北京航空航天大学宇航学院,北京100191

出　　处：《计算力学学报》2011年第5期792-797,共6页Chinese Journal of Computational Mechanics

摘　　要：提出了一种结合FE和SPH的3D冲击破碎问题仿真方法——FE重构法。通过立方体FE单元填充的方式对任意几何体进行离散,并建立粒子-形心重合模型,然后将用LS-dyna软件对粒子模型进行SPH撞击仿真;基于每一个步长的仿真结果,进行FE单元的重构,并结合失效准则进行失效分析,最终得到FE与SPH混合的仿真结果。针对超高速碰撞问题应用FE重构法进行了仿真验证,仿真结果中用FE单元代表未破碎材料,SPH粒子代表破碎材料,可以清晰刻画材料的破碎过程。通过仿真和实验的对比,表明了该方法的可靠性和有效性。并通过对FE与SPH方法的计算公式和计算步骤的分析,论证了FE重构方法与FE转化SPH方法的等价性,为FE重构方法提供了进一步的支持。A combined method of FE and SPH-FE reconstruction-for impact fracture is presented. The arbitrary geometry is filled by cube elements for discretization and particle-centroid-coincided model is built. Particle model is used in the SPH impact simulation by LS-dyna. Elements are reconstructed based on the simulation result of each time step. Failure analysis is applied to the reconstructed FE model and mixed result is finally acquired. HVI problems are computed with FE reconstruction method for calibration. In the result FE elements stand for large fragments while SPH particles stand for small particles. The fragmentation process can be clearly observed in the simulation. Compared with the experiment, FE reconstruction method is proved to be reliable and feasible. Based on the analysis of the FE and SPH principles, FE reconstruction method is proved to be equivalent to the Conversion method. The equivalence provides extra support to the availability and efficiency.

关 键 词：超高速撞击 有限元 SPH 数值仿真 碎片云 

分 类 号：O242.21[理学—计算数学]