裂纹夹杂的几何参数及对复合体弹性模量的影响

Geometric Parameters of Cracked Inclusions and Their Effects on Elastic Modulus of Composites

分析了细观力学中常用的夹杂参数(形状比和体积分数)在研究钱币形裂纹时趋于零的问题,并通过算例加以验证,指出该参数的不适用性.为了更有效地描述裂纹夹杂的几何特征,引入另外两个参数:裂纹面积分数和代表性体积元高宽比,用Mori-Tanaka方法,计算不同几何参数情况下非增强与纤维增强基体中含钱币形裂纹时复合体的弹性模量,讨论了参数的影响,证实了新参数的适用性.

The conventional geometric parameters relevant to inclusions,i.e.,aspect ratio and volume fraction,are unsuitable to the micromechanical study on inclusions if taking the coin-like crack as inclusions of which both the aspect ration and volume fraction approach zero.The fact has been verified via numerical exemplification.So,two other parameters are introduced to describe the geometric characteristics of cracked inclusions,i.e.,the crack area fraction and the aspect ratio of representative volume element.Then,based on Mori-Tanaka method,the elastic modulus is calculated for a composite in which the unreinforced and fiber-reinforced matrices both contain the coin-like cracks as inclusions with different geometric parameters.The applicability of the two new parameters are verified with their effects discussed.