This paper proposes an experimental identification of the parameters of a coupled plasticity-damage model to be used for numerically simulate the mechanical behaviour of an Ultra-High Performance Fibre-Reinforced Concrete (UHPFRC) under impact. In the DFHcoh-KST model, a parabolic relation describes the pressure dependency of yield stresses (in the sense of Von Mises plasticity), and an anisotropic damage model (accounting for strain rate effect and crack bridging of fibre) is used to describe the tensile failure of concrete. This model is implemented in the Finite Element (FE) code Abaqus to simulate the ballistic impact of an AP (Armour-Piercing) projectile. The model parameters are identified under different loading conditions based on quasi-oedometric compression tests, bending tests and spalling tests. Tunnelling and erosion criterion are used in the numerical simulation to overcome the strong element distortions in the FE simulation in the tunnel region. The influence of friction at the projectile-target interface is also discussed. This study shows that yield strength and tensile damage are fundamental to predict the penetration depth of an almost rigid projectile into a UHPFRC target and that the crack bridging of fibre needs to be taken into account to correctly predict the final damage pattern. In contrast, the modelling of the UHPFRC material compaction is found to be negligible due to its low porosity. Finally, numerical results are compared to classical post-mortem observation and a 3D X-ray Computed Tomography (X-ray CT) reconstruction.

本文提出了一种可塑性-损伤耦合模型参数的实验辨识，该模型可用于数值模拟超高性能纤维增强混凝土（UHPFRC）在冲击下的力学性能。在DFHcoh-KST模型中，抛物线关系描述了屈服应力的压力依赖性（在Von Mises塑性的意义上），而各向异性损伤模型（考虑了应变率效应和纤维的裂纹桥接）用于描述拉伸强度。混凝土的破坏。该模型以有限元（FE）代码Abaqus实施，以模拟AP（穿甲弹）弹丸的弹道冲击。基于准测压压缩试验，弯曲试验和剥落试验，在不同载荷条件下确定模型参数。在数值模拟中使用隧穿和侵蚀准则来克服隧道区域有限元模拟中的强元素变形。还讨论了在弹丸-目标界面处的摩擦力的影响。这项研究表明，屈服强度和拉伸损伤是预测几乎刚性弹丸进入UHPFRC目标的渗透深度的基础，并且必须考虑到纤维的裂纹桥接才能正确预测最终的损伤模式。相反，由于其低孔隙率，UHPFRC材料压实的模型被忽略了。最后，将数值结果与经典的验尸观察和3D X射线计算机断层扫描（X射线CT）重建进行比较。