碳纤维强度的计算机研究

COMPUTER STUDIES ON THE STRENGTH OF CARBON FIBERS

本文用计算机程序确定三参数威布尔分布函数中的三个参数，并以实验获得的单丝强度数据比较了三参数威布尔分布和正态分布以及二参数威布尔分布的适用性。结果表明：纤维束中占大多数的中等强度单丝，其强度较符合威布尔分布；少量较低或较高强度单丝较符合正态分布。比较二参数和三参数威布尔分布发现，在某些实验样本范围内，两者相差较少，而在另一些情况下，基本上不能用二参数威布尔函数来描述。为提高统计分析的可靠性，建议采用三参数威布尔分布。另外，本文还进行了纤维束断裂过程的计算机模拟，其结果和实际情况符合得较好。

Due to the difficulty in determining the parameters of the three-parameter Weibull function(WF), only two-parameter WF was commonly used as an approximation. In the present work, a computer program to determine the three parameters of WF was adopted. Using the experimental data, applicabilities of three-parameter Weibull distribution, Normal distribution and two-parameter Weibull distribution were compared. It is demonstrated that the majorities of the single fibers with medium strength obey the Weibull distribution quite well, while fibers with very high or very low strength seem to obey the Normal distribution better. In comparing two- and three-parameter Weibull distributions with the present data, no significant difference was found in some samples, while distinct difference existed in some other samples. To ensurre the reliability of statistical analysis, it is recommended that only the three-parameter WF will be used in the strength analysis. Besides, some computer simulation results of the fracture strength of fiber bow are given, and they fit the experimental data quite well.