单向复合材料在低温下的应力集中及强度

首先采用计及基体拉力的修正剪滞模型,研究了在低温情形下受纵向拉伸荷载作用的单向纤维增强复合材料由部分纤维及基体断裂所导致的应力重新分布。然后采用随机临界核理论,对单向纤维增强复合材料在低温情形下的拉伸破坏过程进行了细观统计分析,定量地研究了低温对拉伸强度的影响。计算结果表明,在低温环境下,E-玻璃纤维和碳纤维复合材料的应力集中因子有不同程度的改变,其强度极限均比常温情形下高。

Stress Concentrations and Strengths of Unidirectional Composites at Cryogenic Temperature

Using a modified shear-lag model taking into account the tensile force in the matrix, the stress redistributions induced by the fracture of some fibers and matrix elements for unidirectionally fiber-reinforced composites subjected to axial tension at cryogenic temperature were studied. On the basis of this, utilizing the random critical-core theory, the micro-statistical analysis for the tensile failure of unidirectionally fiber-reinforced composites at cryogenic temperature was performed. The influence of low temperature on the tensile strength was studied quantitatively. The calculating results show that the variation of the stress concentration factors for both E-glass and carbon fiber composites at cryogenic temperature is different and their strengths are higher than those at normal temperature.