复合材料损伤与断裂力学研究

对纤维增强聚合物基复合材料进行了损伤与断裂力学分析,建立了材料的模型,采用基体横向裂纹的剪切迟滞分析获得较好的基体开裂的定量分析结果;采用边界配置法计算各向异性材料裂纹体的应力强度因子,建立裂纹的扩展判据,并对纤维断裂进行了弹性分析.针对玻璃纤维/酚醛复合材料层板进行了理论和实验分析,得到材质裂纹密度与刚度退化的相关曲线,实验结果验证了理论分析结果的正确性;得到应力强度因子S随裂纹尺度的变化曲线和对纤维断裂和脱胶引起的刚度退化的计算结果.

RESEARCH OF DAMAGE AND FRACTURE MECHANICS FOR COMPOSITE MATERIAL

In this paper, a mechanical analysis of damage and fracture mechanics for fiber-reinforced polymer-matrix composite has been made. In addition, the material model has been built. By means of shear-lag analysis for crack along matrix-transverse orientation, a good result of quantitative analysis for matrix-crack opening has been obtained. With boundary-collocation method, stress-intensity factor of anisotropic-material crack has been calculated. Also the criterion for crack extension has been established. At the same time, an elastic analysis for fiber fracture has been done. In this article, glass-fiber/phenotic delaminated composite plate, as a typical example, has been analyzed theoretically and experimentally. Material-crack density and stiffness-degenerated relevant curve have been attained. Moreover the experimental result has proved the correctness of analytic result theoretically. The curve, which varies with the stress-intensity factor S changing and stiffness-degenerated calculated result because of fiber fracture and coming unglued have been obtained.