Zr基非晶合金JH-2模型的构建及应用

为构建Zr_62.5Nb₃Cu_14.5Ni₁₄Al₆非晶合金在高压、大应变、高应变率状态下的材料模型，采用根据实验数据理论推导和数值模拟对比反馈的方法，对材料的Johnson-Holmquist本构模型（JH-2模型）参数进行了研究:材料的静水压力-体应变关系通过平板冲击实验数据和理论推导得到；无损材料强度与应变、应变率的关系通过轴向压缩实验数据确定；材料损伤参数与破碎材料强度参数的关系通过平板冲击实验数据确定；破碎材料强度参数通过数值模拟与实验结果对比的反馈法得到。将材料模型应用于平板冲击和破片侵彻的数值模拟，通过数值模拟与实验结果对比的方式，验证材料模型的准确性。结果表明，平板冲击实验中，材料的自由面粒子速度曲线与数值模拟结果吻合度较高；破片侵彻实验中，破片对钢靶的侵彻深度、开坑孔径与数值模拟结果的一致性较好，构建的材料模型较准确反映了材料的动态力学特性。

Construction and application of the JH-2 model for a Zr-based bulk metallic glass alloy

Zr-based bulk metallic glass is a type of glass alloy with many excellent properties, such as high strength and high hardness. With the increasing application of Zr-based bulk metallic glass alloys in military field, it is urgent to construct the mechanical models for these materials, including equations of state and constitutive relations. The Johnson-Holmquist constitutive model (JH-2 model) is the most widely used constitutive model to describe the response of brittle materials subjected to high pressures, large strains, and high strain rates. The parameters of the JH-2 model for the Zr_62.5Nb₃Cu_14.5Ni₁₄Al₆ bulk metallic glass alloy were determined by experimental and theoretical methods, as well as “back out” approaches from simulation data. The Hydrostatic pressure-volume strain relationship was developed by theoretical derivation from the results of plate-impact experiments. The results of axial compression tests were used to propose the relationship between the intact strength and strain, strain rate of the material. The relationship between the damage parameters and fracture strength of the material was determined by the plate-impact experiments. The plate-impact data were used to “back out” the fracture strength parameters as well. Numerical simulation results including plate impact and fragment penetration were provided to validate the accuracy and applicability of the developed model. The results show that the particle velocity curve of the freedom surface agrees well with the numerical simulation. The penetration depth and cavity radius obtained in the tests are in good agreement with the numerical simulation results, and the developed model can describe the dynamic properties of the material accurately.