摘要
给出了一种根据亚临界裂纹扩展规律估算钠钙玻璃疲劳强度的方法。结果显示，钠钙玻璃的亚临界裂纹扩展无明显尺寸效应，缺口试件的疲劳强度与试件应力集中系数成反比。
In this paper, a general method for predicting the fatigue strength of soda lime glass is proposed on the basis of the following experimental observations: (1) Identical sub critical crack growth (SCG) behavior of material is observed for both the double cantilevel beam specimen with a long crack and the specimen with an indentation crack. The correlation between the SCG rate and the stress intensity factor K I can be expressed with the power law. (2) The dynamics parameters of the SCG determined from the fracture mechanics approach are the same as those obtained from the dynamic fatigue tests with unnotched specimens. It suggests that the crack growth resistance of natural flaws in the material investigated should be independent of crack size. (3) The notched flexural strength of material is inversely proportional to the stress concentration factor K t of specimens. The fracture stress at notch tip is independent of K t and its value is approximately equal to the flexural strength of unnotched specimens. (4) The curves of the dynamic fatigue strength versus the loading rate obtained from specimens with different stress concentration factors are parallel to each other. (5) When the specimen strength follows Weibull distribution, the modulus m of the distribution is independent of K t but the scale factor σ 0 is inversely proportional to K t . In line with the above experimental results, the fatigue strength of soda lime glass can be predicted with the fracture mechanics approach. By using the concept of equivalent stress σ eq proposed by the authors, the general SPT(strength probability time) diagram for both unnotched and notched specimens is obtained.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
1999年第3期485-488,共4页
Journal of Northwestern Polytechnical University
基金
航空科学基金
陕西省自然科学基金
