延性金属层裂自由面速度曲线物理涵义解读∗

摘要

对延性金属层裂自由面速度曲线上典型特征所蕴含的物理涵义进行了新的解读。揭示了自由面速度曲线上宏观响应特征和微孔洞成核、长大和聚集的微损伤演化动力学之间的关联： Pullback信号的临界点对应于微孔洞的成核,Pullback幅值表征了损伤成核或起始的条件——成核强度； Pullback信号之后的回跳斜率代表了损伤演化速率, Pullback 信号后速度回跳幅值从一定程度上反映了损伤程度； Pullback信号之后的振荡周期模式反映了损伤的局域化状态。%The physical meaning of ductile spall fracture corresponding to the typical properties in free surface velocity curve has been discussed. A correlation between the macroscopic responses and the evolution of mic-damage is established;the pullback signal the found to correspond to the condition for nucleation of voids, and the rate at which the velocity rises to the first peak beyond the minima corresponds to the rate of damage evolution, and by using the velocity period after the the pullback signal we can distinguish the state of damage.