Abstract The present study deals with numerical modeling of strain rate- and pressure-related deformation and damage of plastic-bonded explosives (PBXs). A mechanical constitutive model that combines a porosity model and a recently developed viscoelastic–viscoplastic damage model (Liu et al., 2019) [1] with necessary modifications is presented. The model is calibrated for 1,3,5-triamino-2,4,6-trinitrobenzene-based PBX by using available experimental data under hydrostatic cyclic compression, uniaxial compression at various strain rates, and triaxial compression with hydrostatic confining pressure. The complex behaviors of PBXs, such as irreversible volumetric compaction and coupled effects of strain rate and pressure on mechanical strength and failure mechanism, are investigated through several single-element tests at typical loading conditions and split Hopkinson pressure bar (SHPB) tests with lateral confinement. The model properly captures these behaviors and is able to accurately restitute the loading and reloading process of the confined SHPB test.

中文翻译：

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考虑压力和应变率效应的塑结炸药变形损伤建模

摘要 本研究涉及塑性粘结炸药 (PBX) 应变率和压力相关变形和损伤的数值模拟。提出了一种机械本构模型，该模型结合了孔隙率模型和最近开发的粘弹-粘塑性损伤模型（Liu 等人，2019 年）[1]，并进行了必要的修改。该模型针对基于 1,3,5-三氨基-2,4,6-三硝基苯的 PBX 进行了校准，方法是使用静水循环压缩、各种应变率下的单轴压缩和静水围压三轴压缩下的可用实验数据。PBX 的复杂行为，例如不可逆的体积压实以及应变速率和压力对机械强度和失效机制的耦合影响，通过在典型负载条件下的几个单元测试和带有横向限制的分裂霍普金森压力棒 (SHPB) 测试进行研究。该模型正确地捕捉了这些行为，并能够准确地还原受限 SHPB 测试的加载和重新加载过程。