Sucrose is a commonly used energetic material simulant for $\beta$-HMX. However, its behavior under extreme loading conditions remains poorly understood. Pressure-Shear Plate Impact (PSPI) experiments have been conducted to provide an experimental foundation for developing a suitable constitutive model for sucrose. Experiments have been performed at two different nominal normal stress values, 3 and 9.5 GPa, with nominal shear strain-rates of the order of ${10}^6{s}^{-1}$. Sucrose exhibits a shear strength of ∼400-500 MPa in this pressure range, with a relatively small pressure sensitivity. However, pronounced strain softening is observed in sucrose at sufficiently large shear strains - even a dramatic drop in shearing resistance in some cases. A thermodynamically-consistent constitutive theory is presented to model the thermoelastic, thermo-viscoplastic response of sucrose. The use of the logarithmic strain and an appropriate set of invariants allows for separation of the Cauchy stress into pressure and deviatoric terms. A complete Mie-Gruneisen equation of state is presented to model the volumetric behavior while the deviatoric response is captured through the Johnson-Cook Model. The material model is able to capture experimental observations and predicts localization in the form of adiabatic shear bands, which explains the catastrophic drop in shearing resistance of sucrose observed in the experiments. Such localization events carry important implications for energetic materials in the context of hot-spot formation and underline the importance of dynamic shearing strength measurements.

蔗糖是一种常用的含能材料模拟物 $\beta$-HMX。然而，它在极端负载条件下的行为仍然知之甚少。已经进行了压力剪切板冲击 (PSPI) 实验，为开发合适的蔗糖本构模型提供了实验基础。已在两个不同的标称正应力值（3 GPa 和 9.5 GPa）下进行了实验，标称剪切应变速率为${10}^6{秒}^{-1}$. 蔗糖在该压力范围内的剪切强度约为 400-500 MPa，压力敏感性相对较小。然而，在足够大的剪切应变下在蔗糖中观察到明显的应变软化 - 在某些情况下甚至剪切阻力急剧下降。提出了一种热力学一致的本构理论来模拟蔗糖的热弹性、热粘塑性响应。对数应变和一组适当的不变量的使用允许将柯西应力分离为压力项和偏项。提出了一个完整的 Mie-Gruneisen 状态方程来模拟体积行为，同时通过 Johnson-Cook 模型捕获偏转响应。材料模型能够捕捉实验观察结果并以绝热剪切带的形式预测定位，这解释了在实验中观察到的蔗糖剪切阻力的灾难性下降。在热点形成的背景下，这种定位事件对含能材料具有重要意义，并强调了动态剪切强度测量的重要性。