Wang Yanchao, Chen Dong, Li Nengwen, Yuan Huanquan, Zhu Zengyu, Li Yongxiang, Huang Zhengming
Automotive Engineering Institute, Guangzhou Automobile Group Co., Ltd, Guangzhou, 511434, China.
School of Aerospace Engineering & Applied Mechanics, Tongji University, Shanghai, 200092, China.
Sci Rep. 2020 Jan 21;10(1):847. doi: 10.1038/s41598-020-57771-8.
Nonlinear properties of composite materials are essential for their engineering application. In this work, a three-phase micromechanics bridging model is employed to evaluate the nonlinear behavior of a composite from properties of fiber, matrix and interphase. It is assumed that the matrix elastoplasticity and the interface damage are two major sources of the nonlinearity. The former is described by the J2 flow rule. The latter is approximated by an interphase with stiffness degradation. For an interphase, an equivalent damage stress is introduced to account for the effect of normal and shear stress on the interface damage growth. Further, an explicit empirical equation is developed to relate the equivalent damage stress and the stiffness degradation of an interphase. The present elasto-plastic damage model is validated by comparing with experimental data of a series of composites under off-axis tensile loads.
复合材料的非线性特性对其工程应用至关重要。在这项工作中，采用三相细观力学桥联模型，根据纤维、基体和界面相的性能来评估复合材料的非线性行为。假定基体的弹塑性和界面损伤是非线性的两个主要来源。前者由J2流动法则描述。后者通过具有刚度退化的界面相来近似。对于界面相，引入等效损伤应力来考虑正应力和剪应力对界面损伤扩展的影响。此外，还建立了一个明确的经验方程来关联等效损伤应力与界面相的刚度退化。通过与一系列复合材料在偏轴拉伸载荷下的实验数据进行比较，验证了本文提出的弹塑性损伤模型。
