Micromechanisms of damage in unidirectional fiber reinforced composites: 3D computational analysis
Micromechanisms of damage in unidirectional fiber reinforced composites: 3D computational analysis
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DOI：
10.1016/j.compscitech.2009.01.022
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发表时间：
2009-06
影响因子：
9.1
通讯作者：
L. Mishnaevsky;P. Brøndsted
中科院分区：
文献类型：
--
作者：
L. Mishnaevsky;P. Brøndsted
采用数值细观力学方法研究了玻璃纤维增强复合材料的力学行为和损伤演化。编制了含损伤单元复合材料三维细观力学单胞模型的自动生成程序，并用于数值实验。纤维强度的统计变异性的影响，聚合物基体的粘度以及基体，纤维和界面的损伤过程之间的相互作用进行了数值研究。结果表明，具有恒定强度的纤维确保复合材料在临界前载荷下具有较高的强度，而具有随机分布强度的纤维导致复合材料在临界后载荷下具有较高的强度。在纤维强度随机分布的情况下，纤维中的损伤扩展几乎与基体中裂纹长度无关，而在纤维强度恒定的情况下，基体裂纹对纤维开裂的影响很明显。在模拟中观察到基体开裂和界面脱粘之间的竞争：在界面开裂密集的区域，纤维断裂和基体开裂都被延迟。但在基体长裂纹形成区域，纤维开裂并不导致界面损伤。
Numerical micromechanical investigations of the mechanical behavior and damage evolution of glass fiber reinforced composites are presented. A program code for the automatic generation of 3D micromechanical unit cell models of composites with damageable elements is developed, and used in the numerical experiments. The effect of the statistical variability of fiber strengths, viscosity of the polymer matrix as well as the interaction between the damage processes in matrix, fibers and interface are investigated numerically. It is demonstrated that fibers with constant strength ensure higher strength of a composite at the pre-critical load, while the fibers with randomly distributed strengths lead to the higher strength of the composite at post-critical loads. In the case of randomly distributed fiber strengths, the damage growth in fibers seems to be almost independent from the crack length in matrix, while the influence of matrix cracks on the beginning of fiber cracking is clearly seen for the case of the constant fiber strength. Competition between the matrix cracking and interface debonding was observed in the simulations: in the areas with intensive interface cracking, both fiber fracture and the matrix cracking are delayed. Reversely, in the area, where a long matrix crack is formed, the fiber cracking does not lead to the interface damage.