Abstract Dynamic response and fracture-induced initiation characteristics of aluminum particle filled polytetrafluoroethylene (PTFE/Al) reactive material was studied in two experimental configurations: (a) thin disks for compression and (b) hat-shaped specimens with predesigned shear bands of different widths for compression-shear, at elevated strain rates and temperatures. Compression stress-strain curves demonstrate typical elasto-plastic behavior with prominent strain hardening, strain rate strengthening, as well as thermal softening effects of the material. While growing oscillations and marked strength decrease due to shear band widths decrease observable on the shear stress-strain curves illustrate the localized shear induced adiabatic thermal effect and size effect of polymer materials. Post compression-shear to initiation phenomenon recorded by high-speed photography reveals the necessity of fracture process to initiation, apart from the intense shear work and loading rate effect. Employing the constitutive parameters determined at elevated strain rates and temperatures, 3D full size finite element modeling was performed. On the basis of a good agreement of the simulated and tested shear stress-strain curves for specimens of different shear band widths, a more direct insight into the deformation and stress evolution at the vicinity of the predesigned shear zones was analyzed and obtained.

中文翻译：

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铝粒子填充聚四氟乙烯反应材料帽形试样动态响应及断裂引发特性研究

摘要 在两种实验配置中研究了铝颗粒填充的聚四氟乙烯 (PTFE/Al) 反应材料的动态响应和断裂引发特性：(a) 用于压缩的薄盘和 (b) 具有预先设计的不同宽度剪切带的帽形试样用于压缩剪切，在升高的应变率和温度下。压缩应力-应变曲线展示了典型的弹塑性行为，具有显着的应变硬化、应变率强化以及材料的热软化效应。虽然由于剪切带宽度的减少而导致的振荡增加和强度显着降低，但在剪切应力-应变曲线上可观察到，这说明了聚合物材料的局部剪切引起的绝热热效应和尺寸效应。除了强烈的剪切功和加载速率效应外，高速摄影记录的压缩后剪切到起爆现象揭示了断裂过程到起爆的必要性。利用在升高的应变率和温度下确定的本构参数，进行了 3D 全尺寸有限元建模。基于不同剪切带宽度试样的模拟和测试剪切应力-应变曲线的良好一致性，分析并获得了对预设计剪切带附近的变形和应力演化的更直接了解。进行了 3D 全尺寸有限元建模。基于不同剪切带宽度试样的模拟和测试剪切应力-应变曲线的良好一致性，分析并获得了对预设计剪切带附近的变形和应力演化的更直接了解。进行了 3D 全尺寸有限元建模。基于不同剪切带宽度试样的模拟和测试剪切应力-应变曲线的良好一致性，分析并获得了对预设计剪切带附近的变形和应力演化的更直接了解。