Abstract

A new theoretical energy-based model that predicts the ballistic behavior of thin woven composite laminates is presented. This model formulated for high velocity impacts, where the boundary conditions (applied at the external edges of the impacted plate) do not play a relevant role. This can be assumed as the mechanical waves do not reach the borders during the impact event, being the local structural behavior responsible for the ballistic performance. A non-dimensional formulation is used to analyze the influence of material properties and geometrical parameters in the ballistic response of the laminate. The model is physically-based on the energy contribution of different energy-absorption mechanisms. A 3 D finite element model previously developed is used to simulate the performance of the laminate under high velocity impacts and to validate the hypotheses of the theoretical model. A comparison between FE and theoretical models is performed by means of energy-absorption mechanisms. For that, the failure modes of the FE model are related to the corresponding energy-absorption mechanisms of the theoretical associated. The evaluation of the theoretical results is straightforward although the FEM results require the evaluation of the energy absorbed by each element that fails under each criterion. The predictive capability of the proposed model is verified against experimental results, which were obtained from previous studies carried out by the authors. The results obtained show the dependencies between the ballistic response and the non-dimensional physical parameters of the model. Furthermore, the proposed model can be used to see the relative importance of the different energy-absorption mechanisms involved and the comparison of these mechanisms between the theoretical and the FE models can reflect the different roles played by them, depending on the material properties and geometrical characteristics of the laminate. These results highlight the relevance of the in-plane energy-absorption mechanisms, which rule the penetration process for thin laminates.

摘要

提出了一种新的基于能量的理论模型来预测薄编织复合层压板的弹道行为。该模型适用于高速撞击，其中边界条件（应用于撞击板的外部边缘）不发挥相关作用。这可以假设为机械波在撞击事件期间没有到达边界，这是造成弹道性能的局部结构行为。无量纲公式用于分析材料特性和几何参数对层压板弹道响应的影响。该模型基于物理上不同能量吸收机制的能量贡献。先前开发的 3D 有限元模型用于模拟层压板在高速冲击下的性能，并验证理论模型的假设。有限元模型和理论模型之间的比较是通过能量吸收机制进行的。为此，有限元模型的失效模式与理论相关的相应能量吸收机制有关。理论结果的评估很简单，尽管 FEM 结果需要评估在每个标准下失败的每个元素所吸收的能量。所提出的模型的预测能力通过实验结果进行了验证，实验结果是从作者之前进行的研究中获得的。获得的结果显示了弹道响应与模型的无量纲物理参数之间的相关性。此外，所提出的模型可用于查看所涉及的不同能量吸收机制的相对重要性，并且这些机制在理论模型和有限元模型之间的比较可以反映它们所扮演的不同角色，具体取决于材料特性和几何形状。层压板的特性。这些结果突出了平面内能量吸收机制的相关性，它决定了薄层压板的穿透过程。所提出的模型可用于查看所涉及的不同能量吸收机制的相对重要性，并且这些机制在理论模型和有限元模型之间的比较可以反映它们所扮演的不同角色，具体取决于材料特性和几何特征层压板。这些结果突出了平面内能量吸收机制的相关性，它决定了薄层压板的穿透过程。所提出的模型可用于查看所涉及的不同能量吸收机制的相对重要性，并且这些机制在理论模型和有限元模型之间的比较可以反映它们所扮演的不同角色，具体取决于材料特性和几何特征层压板。这些结果突出了平面内能量吸收机制的相关性，它决定了薄层压板的穿透过程。