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采用有限元法模拟了片层粒子中微裂纹的萌生和扩展过程。模拟结果表明,在特定的基体粗糙表面上,横向裂纹在垂直方向(Y方向)应力作用下沿片层粒子与基体界面附近开裂,横向裂纹平均长度lh=0.37ds(ds为片层粒子直径);而纵向裂纹则由于在片层粒子的腰部区域存在几何突变,在该处呈现出更高的水平方向(X方向)应力,导致裂纹大部分以近乎与基体垂直角度贯穿片层粒子腰部区域,并普遍优先于横向裂纹开裂,纵向裂纹平均长度lv=0.37hs(hs为片层粒子厚度)。研究发现,横向裂纹长度随撞击速度的增大而变长,而纵向裂纹长度随撞击速度的增大而变短。
Finite element method was used to simulate the initiation and propagation of microcracks in lamellar particles. The simulation results show that the transverse cracks crack along the vertical direction (Y direction) along the interface between the lamellar particles and the matrix on the rough surface of the substrate, and the average length of the transverse cracks is lh = 0.37ds (ds is the lamellar particle diameter) While the longitudinal cracks present a higher horizontal (X-direction) stress due to the geometric abrupt change in the waist region of the lamellar particles, resulting in the majority of the cracks penetrating the lumbar region of the lamellar particles at a nearly vertical angle to the substrate, And generally takes precedence over transverse crack initiation. The average longitudinal crack length lv = 0.37 hs (hs is the lamellar particle thickness). The results show that the length of transverse crack increases with the increase of impact velocity, while the length of longitudinal crack decreases with the increase of impact velocity.