摘要
实验测定了正火４５钢切口件的疲劳寿命曲线，给出了具有理论疲劳极限的能覆盖全部寿命范围的疲劳寿命表达式，对实验结果的统计分析表明，同一应力水平下的疲劳寿命遵从对数正态分布。疲劳抗力系数和理论疲劳极限亦遵从对数正态分布。依据疲劳抗力系数和理论疲劳极限的概率分布，求得了Ｐ─△σｅｑｖ─Ｎ曲线表达式，且与实验结果符合很好。根据４５钢的拉伸性能和疲劳极限，对４５钢疲劳寿命进行了估算，估算结果与实验结果符合较好。
The research results presented are based on work done on a project supported by NNSFC (National Natural Science Foundation of China). This NNSFC project has as its objective the replacement of the crude empirical fatigue life design of the widely used Chinese 45 steel (0. 45% carbon steel) with refined one.Our research gives a refined formula, eq. 7 (a), for determining f&tisue life of Chinese 45 steel for a survivability of 50%, which is the only survivability used in crude empirical design. We also give eqs. 7 (b) through 7(e) for other survivabilities (99. 9%, 95%, 0.1%,5%). It is valid to use the above refined formulas since all three parameters - fatigue life, threshold, f&tigue resistance coefficient-obey log-normal distribution. Fig. 4 shows that fatigue lives computed with eqs. 7(a) through7(e) agree quite well with test data; Fig.4 is also very convenient for designers.Incidentally, this paper gives the latest developments of a decade of work begun with the third author's 1986 paper[6], which, in turn, was based on another decade's research ofthe third author.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
1996年第2期179-184,共6页
Journal of Northwestern Polytechnical University
基金
国家自然科学基金
