摘要
本文用显微激光分析仪对纤维复合材料进行透射式光弹研究,发现包括光弹性复合材料在内的纤维复合材料,有不同于已知的均质材料滞后器和偏振器的双折射行为,用仅含一个滞后器的现有光弹理论不能解释,如当模型在平面偏光仪亮场中旋转360°时,透射光强随方位角变化的曲线不是具有四个等高峰的正弦曲线,而是出现两个高峰和两个次高峰,且光强最小值点均不在45°方位。提出具有两个独立滞后器(δ_1,δ_2)的矩阵,由此矩阵所导出的各光弹公式均与实验曲线吻合,可望为复为复合材料内部应力的测定提供新途径。指出包括透明光弹性复合材料在内的纤维复合材料的光弹性研究不宜沿用传统光弹用于均质材料的双折射测量方法。
Birefringent behaviors of some currently used fiber-reinforced composites and transparent filament-resin photoelastic materials were investigated by using a self-made Laser Optical Microscopic Analyzer (LOMA). The birsfringcnt characteristics were estimated based on a I-O curve recorded,where I is the light intensity t ransmit ted normally through polarizers and a specimen, and O is the angle between the principal direction of a specimen and the pass plane of the polarizer.If the polarizers are arranged as a bright-field polariscope, the I-O curve of fiber-reinforced composites is not sinusoidal, but appears a pro-nouced peak, at an angle of it/2, and a smaller maximum, at an angle of π. Moreover the positions for minimum values of I also deflect from the middle point between those of the two maximums. Phenomena like this could not be explained by conventional photoelastic theory which con-cering only an independent retardence(d). A new matrix containing two independent retardences (d1,d2) was put forward, from which a series of formulae relating I, d1 and d2 were deduced and showed exellent agreement with experimental results.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
1989年第2期68-73,96,共7页
Acta Materiae Compositae Sinica
基金
国家自然科学基金青年基金
