Abstract Synergetic deformation behavior between crystal particles and polymeric binders dominates the machinability of energetic materials. In the present work, we elucidate cutting mechanisms of HMX-based polymer bonded explosive (PBX) in orthogonal cutting by numerical simulations based on a cohesive finite element framework. The polygonal HMX crystals with a particle volume fraction of 90% are modeled by a linear elasticity model, while the HTPB binders are described by a rate-independent hyperelastic model coupled with a rate-dependent plasticity model. Furthermore, cohesive elements are implemented in both crystal particles and binders to describe thermal-mechanical coupling-induced material failure behavior in the cutting process of PBX. Simulation results reveal different deformation modes of PBX, as well as their correlations with machining results. Furthermore, it is found that depth of cut has a strong impact on the cutting processes of PBX, in terms of material failure mode, subsurface damage and energy dissipation. These findings provide important guidelines for the design and synthesis of energetic materials with high machinability.

中文翻译：

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聚合物粘结炸药精密切割协同变形的有限元分析

摘要 晶体颗粒和聚合物粘合剂之间的协同变形行为决定了含能材料的可加工性。在目前的工作中，我们通过基于内聚有限元框架的数值模拟阐明了 HMX 基聚合物粘结炸药 (PBX) 在正交切割中的切割机制。颗粒体积分数为 90% 的多边形 HMX 晶体由线性弹性模型建模，而 HTPB 粘合剂由与速率无关的超弹性模型和与速率相关的塑性模型相结合来描述。此外，在晶体颗粒和粘合剂中实施了内聚元素，以描述 PBX 切割过程中热-机械耦合引起的材料失效行为。仿真结果揭示了 PBX 的不同变形模式，以及它们与加工结果的相关性。此外，研究发现切削深度对 PBX 的切削过程有很大的影响，包括材料失效模式、次表面损伤和能量耗散。这些发现为具有高可加工性的含能材料的设计和合成提供了重要的指导。