低温下纤维束及束增强复合材料的应力集中

基于剪滞理论，采用一种六角形纤维束模型，以玻璃纤维和碳纤维束为例，计算了在低温下一纤维束内的纤维应力集中因子，并将此结果与常温下的计算结果进行比较，证实了随着温度的降低，玻璃纤维和碳纤维束中的应力集中会有不同程度改变的结论．采用修正的剪滞分析模型，研究了低温下单向玻璃和碳纤维束增强复合材料由纤维束断裂而导致的应力集中，得到的结果比现有常温下的计算结果更具实际意义，也证实了本文结果的合理性和精确性。

Stress Concentrations for Fiber-Bundle and Bundle-Reinforced Composites at Low Temperature

Based on the shear-lag theory,a hexagonal model of fiber-bundles is first used to analyze the stress concentration of fibers in fiber-bundles at a low temperature. Compared with the results at the normal temperature,the present results verify the conclusion that the stress concentration in glass and carbon fiber-bundles will change as temperature goes down. Then,by using a modified shear-lag model,the stress concentration is evaluated,which is induced by the breakage of fiber-bundles in unidirectional glass and carbon bundle-reinforced composites at a low temperature under the elastic condition. Compared with the existing results at the normal temperature,the present results are of greate significance. Therefore,it can be concluded that the present results are reasonable and accurate.