脆性材料裂纹动态扩展规律的研究

为了研究脆性材料中动态裂纹的扩展规律，本文采用PMMA(有机玻璃)作为试件材料，通过钢板冲击实验和拉格朗日与SPH耦合模拟算法进行研究。在保持其他条件一致的情况下，通过改变冲击速度和初始裂纹角度进行分组实验，然后完全对应实验的冲击条件和试件状态进行分组模拟，最后对比分析。得出主要结论有：脆性材料动态裂纹的扩展形态主要是翼型扩展，还有非翼型的次生裂纹出现，翼型裂纹扩展方向竖直向下，次生裂纹扩展方向趋于水平；动态裂纹的扩展长度随冲击速度以指数趋势增长；试件中次生裂纹的出现，很大程度增加了裂纹扩展长度；翼型裂纹的扩展角度随着初始裂纹角度的增大而减小；拉格朗日与SPH耦合算法，能够逼真显示动态裂纹中翼型裂纹的扩展形态等等。

THE STUDY OF CRACK DYNAMIC PROPAGATION LAW OF BRITTLE MATERIALS

To study the crack dynamics propagation law of brittle materials,this paper used PMMA (plexiglass) as the test piece material,studying through impact experiments and Lagrange simulation algorithm coupled with SPH. Under other conditions consistency, by changing the impact velocity and the angle of initial crack test in group, than corresponds exactly to the impact experimental conditions and the test pieces state made simulation. The main conclusions are: extended form of brittle materials mainly airfoil dynamic crack extension, as well as non-airfoil secondary cracks; airfoil crack vertically downward direction, the direction of crack propagation tends secondary level; dynamic extend the length of the crack with the impact velocity exponential trend growth; specimens appear secondary cracks, to a large extent an increase of crack length; airfoil crack extension angle with increasing initial crack angle decreases; Rugby Long days and SPH coupling algorithms to realistic display dynamic crack propagation wing cracks form and so on.