Passive safety, particularly in the transport industry, requires maximizing the dissipation of energy and minimizing the decelerations undergone by a vehicle following a violent impact (crash). This paper proposes a strategy for identifying an anisotropic local damage criterion in a moderate dynamic loading for Advanced Sheet Molding Compound (A-SMC) composite materials. Multi-scale damage modelling based on the Mori-Tanaka approach is put forward. Previously, the results of an experimental campaign carried out on a range of strain rates varying from quasi static to 200 s⁻¹ were used to identify a probabilistic local damage criterion based on Weibull’s formulation and integrate the effect of damage at a fiber-matrix interface scale. Therefore, the progressive local damage occurring under a fast loading may be described. A two-step homogenization procedure allows describing the strain rate effect on the stress-strain curves. The model gives also rise to the prediction of the progressive anisotropic loss of stiffness. Comparing between the experimental and numerical results confirms the ability of the proposed approach to describe the visco-damage effect (delay of damage threshold and decrease in damage kinetics) emphasized in A-SMC composites.

被动安全，特别是在运输行业中，要求最大程度地消耗能量，并最大程度地减少车辆在剧烈撞击（碰撞）后遭受的减速。本文提出了一种策略，用于在中等动态载荷下识别高级片状模塑料（A-SMC）复合材料的各向异性局部损伤准则。提出了基于森-田中法的多尺度损伤建模。以前，实验活动的结果是在从准静态到200 s ^-1的各种应变率范围内进行的用来基于Weibull公式确定概率局部损伤准则，并在纤维-基质界面尺度上整合损伤的影响。因此，可以描述在快速负载下发生的渐进局部损坏。两步均化程序可以描述应变率对应力-应变曲线的影响。该模型还提出了渐进的各向异性刚度损失的预测。实验结果和数值结果之间的比较证实了所提出的方法能够描述A-SMC复合材料中强调的粘滞效应（损伤阈值的延迟和损伤动力学的降低）。