一种自适应轴对称FEM-SPH耦合算法及其在高速冲击模拟中的应用

An adaptive axisymmetric FEM-SPH coupling algorithm and its application to high velocity impact simulation

为了准确、高效地模拟高速冲击问题,提出了一种自适应轴对称有限元(FEM)-光滑粒子流体动力学(SPH)耦合算法。该算法在初始时刻全部采用FEM计算,在动态变形过程中自动将畸变单元转化为粒子,采用SPH计算。该算法采用一种新的耦合算法实现单元与粒子间的高精度耦合,并应用最小内角转化准则和单元分组转化方式实现单元向粒子的自动转化。计算了几个典型的高速冲击问题:首先,通过计算应力波传播测试了新的单元-粒子耦合算法的精度;然后,通过计算泰勒杆问题验证了自适应耦合算法及相应程序的正确性;最后,计算了弹体侵彻铝板和混凝土板。结果表明:自适应耦合算法计算精度好且效率高,适合模拟高速冲击问题。

An adaptive axisymmetric finite element method（FEM）-smoothed particle hydrodynamics（SPH） coupling algorithm is proposed to accurately and efficiently simulate high velocity impact problems.It uses FEM to calculate at the beginning.During the deformation process,it automatically converts distorted elements to particles and uses SPH for calculation at these regions where distorted elements appear.In the adaptive coupling algorithm,a new coupling algorithm is applied to link elements and particles accurately,and a minimum interior angle criterion combined with a group-based conversion manner is adopted to convert elements to particles.Several typical high velocity impact problems are calculated.Firstly,the stress wave propagation is calculated to test the accuracy of the new element-particle coupling algorithm.Then,the Taylor test is calculated to validate the adaptive coupling algorithm and the corresponding code.Finally,the simulation of projectiles penetrating aluminum and concrete plates is presented.The results show that the adaptive coupling algorithm is accurate and efficient and it is very suitable for the simulation of high velocity impact.