准脆性纺织复合材料的谱刚度微平面模型
Spectral Stiffness Microplane Model for Quasibrittle Textile Composites
摘要：
本文提出了一个通用的本构模型来模拟纺织复合材料的正交各向异性刚度、峰前非线性、失效包络线以及峰后软化和断裂。在微平面模型框架下，本构关系用作用于材料细观结构内几个方向的平面上的应力和应变矢量来表示。该模型利用正交各向异性刚度张量的谱分解来定义微平面水平的正交应变模式。这些与中尺度的各种成分和对不同类型变形的材料响应有关。应变相关的本构方程被用来关联的微平面本征应力和本征应变，而变分原理被应用到关联的微平面应力在细观尺度的连续张量在宏观尺度。由于这些功能，所得到的光谱刚度微平面配方可以很容易地捕捉各种物理非弹性现象的纤维和纺织复合材料的典型，如：基体微裂纹，微分层，裂纹桥接，拔出，和脱粘。该模型的应用程序，以一个EST-2 $\times$ 2表明，它可以现实地预测其单轴以及多轴的行为。此外，该模型显示出良好的协议与复合材料管的轴向破碎的实验，这种能力使其成为一个有价值的耐撞性应用的设计工具。该公式计算效率高，易于校准，并适用于其他类型的复合材料结构的巨大的当前利益，如2D和3D编织或3D编织纺织品。
英文摘要：
The present contribution proposes a general constitutive model to simulate the orthotropic stiffness, pre-peak nonlinearity, failure envelopes, and the post-peak softening and fracture of textile composites. Following the microplane model framework, the constitutive laws are formulated in terms of stress and strain vectors acting on planes of several orientations within the material meso-structure. The model exploits the spectral decomposition of the orthotropic stiffness tensor to define orthogonal strain modes at the microplane level. These are associated to the various constituents at the mesoscale and to the material response to different types of deformation. Strain-dependent constitutive equations are used to relate the microplane eigenstresses and eigenstrains while a variational principle is applied to relate the microplane stresses at the mesoscale to the continuum tensor at the macroscale. Thanks to these features, the resulting spectral stiffness microplane formulation can easily capture various physical inelastic phenomena typical of fiber and textile composites such as: matrix microcracking, micro-delamination, crack bridging, pullout, and debonding. The application of the model to a twill 2$\times$2 shows that it can realistically predict its uniaxial as well as multi-axial behavior. Furthermore, the model shows excellent agreement with experiments on the axial crushing of composite tubes, this capability making it a valuable design tool for crashworthiness applications. The formulation is computationally efficient, easy to calibrate and adaptable to other kinds of composite architectures of great current interest such as 2D and 3D braids or 3D woven textiles.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
