This article addresses dynamic behaviour of fibre reinforced polymer composites in terms of a transversely isotropic viscoelastic-viscoplastic constitutive model established at the unidirectional ply level. The model captures the prelocalized response of the ply in terms of rate dependent elasticity and strength without damage. A major novelty is that the model draws from computational homogenization, with matrix and fibre materials as subscale constituents for a representative volume element of the ply. The micromechanics of the strain rate dependent polymer matrix is represented by an isotropic pressure sensitive viscoelastic-viscoplastic prototype model. For the fibre material, transverse elasticity is assumed. The constituents are homogenized via the fluctuating strain of the subscale, where a simple ansatz is applied to allow for constant stress in the plane transverse to the fibre orientation. Despite the relatively simple modelling assumptions for the constituents, the homogenized model compares favourably to experimental data for an epoxy/carbon fibre based composite, subjected to a variety of challenging uniaxial off-axis tests. The model response clearly reflects observed strain rate dependencies under both tensile and compressive loadings.

中文翻译：

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基于微观力学的单向复合材料应变率效应模型

本文根据在单向层级建立的横向各向同性粘弹-粘塑性本构模型来讨论纤维增强聚合物复合材料的动态行为。该模型根据速率相关的弹性和强度来捕获层的预定位响应，而不会造成损坏。一个主要的新颖之处在于该模型借鉴了计算均质化，将基质和纤维材料作为层的代表性体积元素的次尺度成分。应变率相关聚合物基体的微观力学由各向同性压敏粘弹-粘塑性原型模型表示。对于纤维材料，假定横向弹性。成分通过子尺度的波动应变均质化，其中应用简单的 ansatz 以允许横向于纤维取向的平面中的恒定应力。尽管成分的建模假设相对简单，但均质模型与基于环氧树脂/碳纤维的复合材料的实验数据相比具有优势，经受了各种具有挑战性的单轴离轴测试。模型响应清楚地反映了在拉伸和压缩载荷下观察到的应变率依赖性。