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应用断裂力学在拉力负载和弯曲负载下予计石墨强度的研究曾同实验数据和当前广泛采用的威布尔(Weibull)理论进行比较。对尺寸相似的试样,用上述几种方法可以进行比较,但对尺寸差异大的试样威布尔法则不能予计出所观察到的效果。对此进行讨论,说明由于表面缺陷致使材料破坏,使得威布尔理论(体积裂缝分布理论)不适用于这种情况。石墨捧的检验表明了穿过材料的缺陷尺寸的公布情况,致使石墨棒内部强度低于外部强度。实验结果证实了这个予计。但在它作为石墨材料设计方法加以推荐以前,要进一步进行断裂力学检验。
The application of fracture mechanics to calculate the graphite strength under tensile and bending loads has been compared with the experimental data and the widely used Weibull theory. The similar size of the sample, with the above methods can be compared, but for large differences in the size of the sample Weibull rule can not be counted out the observed effect. This discussion is made to show that the Weibull theory (volumetric fracture distribution theory) is not suitable for this situation because of the material failure caused by surface defects. Examination of the graphite plate indicates the release of the defect size through the material, resulting in a lower internal strength of the graphite rod than the external strength. The experimental results confirm this expectation. However, before it is recommended as a graphite material design method, fracture mechanics tests should be further carried out.