基于四分之一象限光强法热解碳消光角的计算机测量方法

 针对C/C复合材料中圆周沉积热解碳的消光特性,根据四分之一象限光强法测量原理提出了一种基于灰度曲线极值变化的热解碳消光角计算机测量方法。开发了一种动态模版匹配算法以修正图像采集中产生的目标位置偏移,并通过图像序列纤维截面形状校正解决了纤维倾斜截面的灰度信息提取问题。此方法能够有效地实现C/C复合材料消光角的计算机测量,且同时适用于纤维垂直截面及倾斜截面的情况。测量结果符合四分之一象限光强法的原理,与目测结果之间的误差位于1°~2°以内,随着热解碳内部微观结构原子排列的有序度及热解碳粒子间的夹角增加,消光十字分叉现象愈加明显,偏光图像纹理复杂程度增加,肉眼观测干扰增大,观测值与测量值之间的误差随之增加。

Measurement of Extinction Angle of Pyrocarbon by One Diagonal Quarter Intensity Principle

In accordance with the extinction characteristics of pyrocarbons deposited around carbon fibers,this paper proposes a method for measurement of the extinction angle based on the one diagonal quarter intensity principle.It develops a dynamic template matching algorithm during image processing for the purpose of amending the bias of the observed patterns.Meanwhile,the problem of gray information extraction is solved for ellipse sections through rectifying the shape of fiber sections in image sequences.The proposed method can achieve the measurement of extinction angles accurately and effectively,which is suitable for both the condition of vertical section and inclined section.The errors between the values measured by the proposed method and observation are within 1°-2°,which increase with the degree of complexity of the polarized light microscopy(PLM) image texture.