Influence of Loading Kinetics on the Shock Response of Polycrystalline Copper
Influence of Loading Kinetics on the Shock Response of Polycrystalline Copper
复制标题
加载动力学对多晶铜冲击响应的影响
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
C. Bronkhorst
中科院分区：
文献类型：
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作者：
J. Escobedo;C. Trujillo;D. Dennis;E. Cerreta;C. Bronkhorst
本文研究了冲击加载动力学对Cu试样损伤演化早期阶段的影响。通过控制平板冲击实验中飞片的几何形状和材料来调整拉伸载荷特性。本研究中使用的所有Cu试样具有相似的显微组织，平均晶粒尺寸为100μm。这项工作表明，冲击脉冲提供的能量和消耗在其耗散的时间的相互作用似乎是负责合成损伤场的特性。对于能量 * 时间的耦合参数的值的增加，损伤场出现从损伤的早期阶段，在空洞成核和初始空洞生长的形式，空洞合并阶段的演变。在这方面，观察到的能量 * 时间的最高值的损伤场组成的合并良好的空隙，这创造了一个几乎完整的断裂面。此外，一个框架中，假设损伤发展可以预测从实时，连续水平的响应测量，即自由表面速度。在此框架下，良好的协议之间的特性的自由表面速度和预测，以及实验观察到的损伤场。
This work examined the effect of shock loading kinetics on the early stages of damage evolution in Cu samples. The tensile loading characteristics were tailored by controlling the geometry and material used for the flyer plates in the plate impact experiments. All the Cu specimens used in this study had similar microstructures with an average grain size of 100μm. This work has shown that the interplay of the energy supplied by the shock impulse and the time spent in its dissipation seem to be responsible for the characteristics of the resultant damage fields. For an increasing value in the coupled parameter of energy*time, the damage fields appear to evolve from the early stages of damage, in the form of void nucleation and initial void growth, to the void coalescence stage. In this regard, a damage field consisting of well-coalesced voids, which created a nearly complete fracture surface, was observed for the highest value of energy*time. Additionally, a framework is postulated in which damage development can be predicted from the real-time, continuum level response measurements, i.e. free surface velocity. Under this framework, good agreement between the characteristics of the free surface velocities and the predicted, as well as the experimentally observed, damage fields is found.