A New Proposal for Retarding Fatigue Crack Reinitiation and Growth from Crack-Tip Introduced Stop-Drilled Hole by Providing Additional Holes
Anggit MURDANICChobin MAKABECAkihide SAIMOTOCTatsujiro MIYAZAKI and Ryouji KONDOU
Abstract:The purpose of present study is to propose a new technical method for retarding fatigue crack reinitiation and growth from the crack tip introduced-stop-drilled hole by providing additional holes. To demonstrate the validity of the proposal, analyses using software for two-dimensional elastic problems based on body-force method were done. Furthermore, a series of experiments was carried out for comparison. The calculated results showed that the additional holes give positive or negative effects on lowering stress concentration at the stop-drilled hole, which varies depending on combination of arrangement and size of both holes. Calking pin into the additional holes which yields internal pressure on the periphery, was found also advantageous for reducing stress concentration at the drilled hole. Finally, the calculated results showed relatively good agreement with the experimental results. Key Words:Fatigue, Retardation, Crack reinitiation, Stop-drilled hole, Additional holes, Stress concentration