{"title":"Cold expansion fatigue performance investigations of GH4169 inclined hole structures using numerical and experimental methods","authors":"Hangjie Shi, Yangjie Zuo","doi":"10.1016/j.ijfatigue.2024.108736","DOIUrl":null,"url":null,"abstract":"In this paper, the inclined cold expansion (ICE) method of superalloy open hole structures was proposed, which provided valuable insights for the life improvement of aero-engine inclined hole structures. The improvements in the static and fatigue properties of GH4169 specimens with inclined holes were characterized. In addition, tensile and fatigue tests were carried out, and the surface strains were assessed by digital image correlation (DIC). The stiffness degradation and fatigue fracture behavior of GH4169 specimens with inclined holes were also discussed. The results showed that ICE could cause the expansion of inclined hole structures and the enlargement of bulges, resulting in tangential residual compressive stress at the hole edge. With the increase of the hole inclinations, the residual stress of the specimen was more uneven in radial direction, while more uniform in axial direction. The fatigue life of the strengthened all increased under three loading levels. The crack initiation zone moved near the entrance layer after ICE. Moreover, ICE increased the crack growth zone, and significantly inhibited the crack growth rate and stiffness degradation rate.","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"15 1","pages":""},"PeriodicalIF":5.7000,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Fatigue","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1016/j.ijfatigue.2024.108736","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
In this paper, the inclined cold expansion (ICE) method of superalloy open hole structures was proposed, which provided valuable insights for the life improvement of aero-engine inclined hole structures. The improvements in the static and fatigue properties of GH4169 specimens with inclined holes were characterized. In addition, tensile and fatigue tests were carried out, and the surface strains were assessed by digital image correlation (DIC). The stiffness degradation and fatigue fracture behavior of GH4169 specimens with inclined holes were also discussed. The results showed that ICE could cause the expansion of inclined hole structures and the enlargement of bulges, resulting in tangential residual compressive stress at the hole edge. With the increase of the hole inclinations, the residual stress of the specimen was more uneven in radial direction, while more uniform in axial direction. The fatigue life of the strengthened all increased under three loading levels. The crack initiation zone moved near the entrance layer after ICE. Moreover, ICE increased the crack growth zone, and significantly inhibited the crack growth rate and stiffness degradation rate.
期刊介绍:
Typical subjects discussed in International Journal of Fatigue address:
Novel fatigue testing and characterization methods (new kinds of fatigue tests, critical evaluation of existing methods, in situ measurement of fatigue degradation, non-contact field measurements)
Multiaxial fatigue and complex loading effects of materials and structures, exploring state-of-the-art concepts in degradation under cyclic loading
Fatigue in the very high cycle regime, including failure mode transitions from surface to subsurface, effects of surface treatment, processing, and loading conditions
Modeling (including degradation processes and related driving forces, multiscale/multi-resolution methods, computational hierarchical and concurrent methods for coupled component and material responses, novel methods for notch root analysis, fracture mechanics, damage mechanics, crack growth kinetics, life prediction and durability, and prediction of stochastic fatigue behavior reflecting microstructure and service conditions)
Models for early stages of fatigue crack formation and growth that explicitly consider microstructure and relevant materials science aspects
Understanding the influence or manufacturing and processing route on fatigue degradation, and embedding this understanding in more predictive schemes for mitigation and design against fatigue
Prognosis and damage state awareness (including sensors, monitoring, methodology, interactive control, accelerated methods, data interpretation)
Applications of technologies associated with fatigue and their implications for structural integrity and reliability. This includes issues related to design, operation and maintenance, i.e., life cycle engineering
Smart materials and structures that can sense and mitigate fatigue degradation
Fatigue of devices and structures at small scales, including effects of process route and surfaces/interfaces.