Department of Theoretical Physics, University of Debrecen, P. O. Box:5, H-4010 Debrecen, Hungary.
Phys Rev Lett. 2010 Mar 5;104(9):095502. doi: 10.1103/PhysRevLett.104.095502. Epub 2010 Mar 3.
We present an experimental and theoretical study of the fragmentation of polymeric materials by impacting polypropylene particles of spherical shape against a hard wall. Experiments reveal a power law mass distribution of fragments with an exponent close to 1.2, which is significantly different from the known exponents of three-dimensional bulk materials. A 3D discrete element model is introduced which reproduces both the large permanent deformation of the polymer during impact and the novel value of the mass distribution exponent. We demonstrate that the dominance of shear in the crack formation and the plastic response of the material are the key features which give rise to the emergence of the novel universality class of fragmentation phenomena.
我们通过将球形聚丙烯颗粒撞击坚硬的墙壁来研究聚合物材料的破碎，进行了实验和理论研究。实验揭示了碎片的质量分布呈幂律分布，指数接近 1.2，与已知的三维块状材料的指数有显著的不同。我们引入了一个 3D 离散元模型，该模型再现了聚合物在冲击过程中的大永久变形和质量分布指数的新值。我们证明了在裂缝形成和材料的塑性响应中剪切的主导地位是导致破碎现象出现新的普适类的关键特征。
