Abstract The development of new generations of propellants with better energetic properties may be hampered by unsatisfactory mechanical behaviors in terms of strength and toughness. A micromechanical approach is adopted to provide a better understanding of the existing links between the constitutive phase behaviors and the local damage, and the macroscopic mechanical behavior of these materials. Three model materials have been made and tested in uniaxial tension. The stress-strain responses were recorded while monitoring their volume changes that quantify the macroscopic damage. A qualitative description of the local damage was obtained thanks to scanning electron microscopy images of samples under loading. The micromechanical approach consists in finite elements analyses on periodic microstructures of non-regular polyhedral particles embedded in a soft matrix. An original microstructure generation tool has been developed specifically in order to obtain highly filled isotropic microstructures. Debonding at the matrix/filler interface was taken into account with a cohesive-zone model (CZM). The impact of the CZM parameters is discussed, in an effort to make the link between the CZM parameters and how the local damage appears and develops, and between the cohesive behavior and the shape of the macroscopic stress-stretch responses of the heterogeneous materials.

中文翻译：

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使用微机械方法了解固体推进剂的机械行为

摘要 具有更好能量特性的新一代推进剂的开发可能会受到强度和韧性方面不令人满意的机械性能的阻碍。采用微观力学方法可以更好地理解本构相行为与局部损伤之间的现有联系，以及这些材料的宏观力学行为。已经制作了三种模型材料并在单轴拉伸下进行了测试。在监测量化宏观损伤的体积变化的同时记录应力-应变响应。由于负载下样品的扫描电子显微镜图像，获得了局部损坏的定性描述。微机械方法包括对嵌入软基体中的非规则多面体粒子的周期性微观结构进行有限元分析。为了获得高度填充的各向同性微观结构，专门开发了一种原始的微观结构生成工具。使用内聚区模型 (CZM) 考虑了基质/填料界面处的脱粘。讨论了 CZM 参数的影响，努力在 CZM 参数与局部损伤的出现和发展方式之间，以及内聚行为与异质材料的宏观应力-拉伸响应形状之间建立联系。使用内聚区模型 (CZM) 考虑了基质/填料界面的脱粘。讨论了 CZM 参数的影响，努力在 CZM 参数与局部损伤的出现和发展方式之间，以及内聚行为与异质材料的宏观应力-拉伸响应形状之间建立联系。使用内聚区模型 (CZM) 考虑了基质/填料界面的脱粘。讨论了 CZM 参数的影响，努力在 CZM 参数与局部损伤的出现和发展方式之间，以及内聚行为与异质材料的宏观应力-拉伸响应形状之间建立联系。