摘要
具有平面负泊松比的石墨纤维／环氧树脂非平衡层合复合材料具有很高的断裂韧性和缺口断裂强度，这一点已被实验所证实。本文用复变函数——变分方法计算了负泊松比材料裂纹尖端的应力场和应力强度因子，并与常规的平衡复合材料进行了比较。负泊松比材料铺层为［０／１５／７５／１５］ｓ，［０／２５／６５／２５］ｓ；常规复合材料铺层为［０／６０／９０／－６０］ｓ。本文重点研究了主应力方向与纤维方向的夹角以及应力强度因子与断裂韧性的关系。分析结果表明：负泊松比材料的缺口断裂强度高于常规铺层复合材料的缺口断裂强度。
It had been proved experimentally that Graphite(AS4)/Epoxy(3501-6) unbalanced laminates with inplane negative Poisson’s ratio have higher fracture toughness and notch fracture strength. In this paper, a study is made of the near tip stress fields for crack and the stress intensity factors in unbalanced laminates with inplane negative Poisson’s ratio by the complex variable variational method. The results obtained are compared with the results of balanced laminates. Three layups, [0/15/75/15] s, [0/25/65/25] s with negative Poisson’s ratio and [0/60/90/-60] s with positive Poisson’s ratio are analysed. Emphasis is put on research into the relations between principal stress’s orientations and fiber’s orientations as well as between stress intensity factors and fracture toughness. The calculation results show that these laminates with negative Poisson’s ratio have higher notch fracture strength.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
1996年第3期111-116,共6页
Acta Materiae Compositae Sinica
基金
国家自然科学基金
洛阳工学院青年科研基金
关键词
负泊松比
裂纹
应力场
断裂强度
复合材料
negative Poisson’s ratio, crack, stress field, fracture strength, composite
