On the miner's damage hypothesis in notched specimens with emphasis on scatter of fatigue life

✍ Scribed by Sakae Tanaka; Satoshi Akita

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 589 KB
• Volume: 7
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(75)90048-x

✦ Synopsis

The subject of cumulative damage in fatigue is extremely complex and various discussions have been ti

for the conformity of experimental results with Miner's linear damage hypothesis. It seems, however, that one of the liitotions of the conventional lii damage rok is that the nominal cyck ratio based on the mean vable of scatter of fatignc life for a group of spccimeas does not represent the correct cycle ratio for individual specimen. The object of this study is to propose a method to evahutc thc.cwnuktive cycle ratio for each particular specimen, with emphasis on scatter of life. According to the statistkal considerations of crack propa@m curves obtained experimcataUy with a large number of mikl &eel notched specimens, it is continned that fat@ life of individual specimen will be estimated from the rate of crack growth at earlier stage of fatigue. From the results of two-kvel sttp tests, it is shown that the inherent cumulative cyck ratio for each specimen is cakulated, and it also enables to evaluate the e&t due to stress interaction associated with change of stress level.