Mechanics and Mechanisms of Thermo-Mechanical Fatigue Failure Relevant to Materials, Structures and Thermal Field.

2015 Fiscal Year Final Research Report

• Project/Area Number: 25249003
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Materials/Mechanics of materials
• Research Institution: Nagaoka University of Technology
• Principal Investigator: OKAZAKI Masakazu 長岡技術科学大学, 工学(系)研究科(研究院), 教授 (00134974)
• Co-Investigator(Kenkyū-buntansha): SAKAGUCHI Motoki 東京工業大学, 大学院理工学研究科, 准教授 (60452083) ; SYAMAGISHI Satoshi 長岡技術科学大学, 大学院工学研究科, 助教 (20452089)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 熱機械的疲労 / 熱/温度場/力学場の連成 / 熱源温度場変動誘起熱応力 / ガスタービン / 超高温部材 / 遮熱コーティング / 分散エネルギーと負荷変動 / 損傷と損傷マップ

Outline of Final Research Achievements

A new testing system has been developed which enables us to apply mechanical loadings superimposed with thermal loadings to the superalloy specimens with cooling systems and thermal barrier coatings (TBCs) in a simulated combustion gas environment. Some specific thermo-mechanical fatigue (TMF) and creep tests were carried out to understand the failure features under the significant thermal gradient (TG) conditions. Special focus was also put on an inteaction between low-cycle and high-cycle fatigue (LCF/HCF) loadings. The xperimental works clearly demonstrated that some specific behaviors were got pronounced in the superalloy substrate and the TBCs under a significant TG. The additional damages were accounted when the TG was coupled with the influence of the DBTT of the bond coat. Mechanistic discussion was also made to condense these knowlege into engineering damage map for life assessment of advanced gas turbine blades subjected to more significant TG conditions.

Free Research Field

高熱材料強度学