通过建立紧密连接且随机分布在指定区域内的圆盘形颗粒离散单元的力学模型来研究单晶硅的力学性能,并采用不同尺寸的离散元模型研究力学性能尺寸效应。结果表明:泊松比、单轴抗压强度、弹性模量以及断裂韧性的尺寸效应不明显,弯曲强度则随着模型尺寸的增大而减小。建立了连续体经典断裂力学有限宽板条单边直裂纹的离散元力学模型,改变初始裂纹长度进行模拟得到的结果与单边切口梁模拟结果及文献报道的试验值一致。
The mechanics models formed by packed circular discrete elements and randomly distributed in a specified region were used to investigate the mechanics properties of monocrystalle-silicon,and some different sizes of discrete element model were carried out to study the size effect of mechanics properties.The simulation results suggest that there is no obvious size effect for Poisson's ratio,compressive strength and Young's modulus and fracture toughness.However,the value of flexural strength decreases with the increasing of the model size.The discrete element model of classical continuum fracture mechanics was used to simulate the fracture process of single edge vertical crack plate with finite-width under tensile stress in infinite distance.The simulation results which obtained by changing the initiate crack length of model are just the same with the simulation results of single edge notched bending(SENB) and the experimental values reported in other literatures.