A physically-based constitutive model for the shear-dominated response and strain rate effect of carbon fibre reinforced composites
A physically-based constitutive model for the shear-dominated response and strain rate effect of carbon fibre reinforced composites
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DOI：
10.1016/j.compositesb.2020.108032
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发表时间：
2020-07-15
影响因子：
13.1
通讯作者：
Liu, Burigede
中科院分区：
文献类型：
--
作者：
Tan, Wei;Liu, Burigede
碳纤维增强塑料(CFRP)的剪切主导变形通常具有显著的硬化响应。这种非线性响应通常通过将应变硬化定律与实验应力-应变曲线进行拟合来模拟。受晶体塑性框架的启发，建立了一种细观力学激励的本构模型来描述碳纤维复合材料在有限应变变形和不同应变率下的剪切和纤维旋转过程。通过尺度函数模拟了剪切模数和屈服强度对应变率的依赖关系。该物理本构模型首先通过简单的剪切和横向压缩试验进行验证，然后根据单向(UD)和交叉铺设复合材料层合板在准静态和动态离轴加载下的实测应力-应变响应进行综合验证。CFRP层板在简单剪切载荷作用下的有限元预测和分析模型证实，初始屈服由基体的剪切屈服强度决定，而硬化行为取决于碳纤维的模数和转角。该模型准确地预测了不同应变率下CFRP离轴加载下的非线性行为，而不需要曲线拟合的应变硬化定律。
A significant hardening response is often observed for the shear-dominated deformation of Carbon Fibre Reinforced Plastics (CFRP). This non-linear response is typically modelled by fitting a strain hardening law against experimental stress-strain curves. Inspired by crystal plasticity framework, we develop a micro-mechanically motivated constitutive model to capture the matrix shearing and fibre rotation of CFRP under finite strain deformation and different strain rates. Strain rate dependency of the shear modulus and yield strength of the matrix was modelled through scaling functions. This physically-based constitutive model is first verified by simple shear and transverse compression tests, followed by comprehensive validations against the measured stress-strain responses of unidirectional (UD) and cross-ply composite laminates subjected to quasi-static and dynamic off-axis loading. The finite element predictions and analytical models of CFRP lamina under simple shear loading confirms that the initial yielding is governed by the shear yield strength of matrix, while the hardening behaviour is dependent on the modulus and rotation of carbon fibres. This model accurately predicts the non-linear behaviour of CFRP under off-axis loading at different strain rates, without the need of a curvefitted strain hardening law.