基于SPH-FEM转换算法的7.62mm步枪弹冲击30CrMnSiA钢板的数值计算
A 7.62 mm Rifle Bullet Impacting on a 30CrMnSiA Steel Target Plate:SPH-FEM Conversion Algorithm
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摘要: 从转换判据和时间步长控制两个方面对光滑粒子流体动力学-有限元(SPH-FEM)转换算法进行改进,采用改进的SPH-FEM转换算法对7.62 mm步枪弹冲击特殊热处理的30CrMnSiA钢板进行全尺寸三维数值计算,将子弹在冲击过程中发生严重畸变的有限单元转换为SPH粒子继续参与计算.子弹采用弹塑性模型,靶板采用修正的Johnson-Cook强度模型和Gruneisen状态方程.针对不同的子弹初速,计算靶板盘形凹陷和冲塞两种破坏模式,计算结果与实验结果吻合较好.表明改进的SPH-FEM转换算法能够合理高效地利用有限单元和SPH粒子,为低强度子弹冲击高强度靶板的计算提供一种有效途径.Abstract: Conversion criterion and time step control are corrected for smoothed particle hydrodynamics-finite element method (SPH-FEM) conversion algorithm. Impact of a 7.62 mm rifle bullet against a special heat treated 30CrMnSiA steel target plate is simulated in full-size in 3D using the corrected SPH-FEM conversion algorithm, in which distorted finite elements of the bullet are converted into SPH particles. An elastic-plasticity model is used for bullet, and corrected Johnson-Cook and Gruneisen EOS are used for target. Two destroyed modes of disc-shape plastic deformation and plugging perforation are calculated for different initial velocities of bullet. Good agreement between numerical results and experimental observations shows that the corrected SPH-FEM conversion algorithm could use finite elements and SPH particles efficiently, which provides an effective tool for simulation of a soft core bullet impacting on a hard plate.