复合材料中加捻纤维束的预应力效应

利用加捻纤维束的力学性能,可以制成预应力复合材料.在不受外力的情况下,这种复合材料的基体受压应力的控制.当有拉伸力作用的时候,材料所受的拉应力值会大大减少,这样,利用这种现象可以提高纤维增强复合材料的抗拉强度.本文将分析连续的加捻纤维束受拉状况并考虑到材料固化后产生的残余应力的影响.这种方法所产生的预应力取决于纤维束的加捻程度.本文将给出计算这种预应力的方法,而且还提供加捻纤维束产生预应力的光弹测试结果以及这种纤维预应力复合材料的纤维破坏的特征.

PRESTRESSING EFFECT OF TWISTED FIBER YARN IN COMPOSITES

By utilizing the behavior of twisted fiber yarn,prestressing composites can be made.In unloading,the matrix of the prestressing composite is applied in compression.If tensile load acts on the composite,the value of the tensile stress acting on the materials may decrease greatly.By tw(?)sted fiber yarn,there- fore,the tensile strength of the composites can be improved.An analysis for extension of continuous fi-ber yarns is made here and residual stress after curing is taken into account.The prestressing intensity inthe composite depends on the twist of fiber yarn.The photoelastic test and the analysis of electronmicrograph are performed,and the theoretical method for calculating prestressing effect is presented inthis paper.