This work develops an elastic-viscoplastic constitutive formulation to the mechanical behavior of polycrystalline FCC metals subjected to high-strain-rate cold deformation, with application to aluminum AA1050. Following a phenomenological approach, the model can account for important macroscopic features related to the mechanical response of ductile metals subjected to high-velocity plastic deformations, such as: (i) strain-hardening; (ii) strain-rate-hardening; and (iii) instantaneous flow stress rate-sensitivity. As a novelty of this proposal, memory effects corresponding to past strain-rate history are considered to affect both the level and rate of material hardening. Another new aspect is the phenomenological representation of both the thermal activation and dislocation drag mechanisms influencing the instantaneous flow stress response. The model calibration and its validation are performed based upon experimental data for commercial pure aluminum AA1050 for wide strain and strain-rate ranges. In comparison with experiments, the proposed model provides suitable predictions for both continuous and sequential compression tests. Overall, due to its relative simplicity and constitutive capabilities, the proposed model proves to be a potential constitutive alternative to simulate engineering problems involving dynamic plastic deformations.

这项工作针对多晶FCC金属在高应变速率冷变形下的机械性能，开发了一种弹性-粘塑性的本构配方，并将其应用于铝A1050。遵循现象学方法，该模型可以解释与韧性金属在高速塑性变形作用下的机械响应有关的重要宏观特征，例如：（i）应变硬化；（ii）应变速率硬化；（iii）瞬时流动应力率敏感性。作为该建议的新颖之处，认为与过去应变速率历史相对应的记忆效应会影响材料硬化的水平和速率。另一个新的方面是影响瞬时流应力响应的热活化和位错阻力机制的现象学表示。基于广泛的应变和应变速率范围内的商业纯铝A1050的实验数据，进行了模型校准及其验证。与实验相比，该模型为连续和顺序压缩测试提供了合适的预测。总体而言，由于其相对简单和本构能力，该模型被证明是模拟涉及动态塑性变形的工程问题的潜在本构选择。