TY - GEN
T1 - Fe analysis of the effects of tgo thickness and interface asperity on the cracking behavior between the tgo and the bond coat
AU - Jiang, Jishen
AU - Xu, Bingqian
AU - Wang, Weizhe
AU - Adjei, Richard Amankwa
AU - Zhao, Xiaofeng
AU - Liu, Yingzheng
N1 - Publisher Copyright:
© Copyright 2016 by ASME.
PY - 2016
Y1 - 2016
N2 - Finite element simulations based on an interface cohesive zone model (CZM) have been developed to mimic the interfacial cracking behavior between the α-Al2O3 thermally grown oxide (TGO) and the aluminum rich Pt-Al metallic bond coat (BC) during cooling from high temperature to ambient temperature. A two dimensional half-periodic sinusoidal geometry corresponding to interface undulation is modelled. The effects of TGO thickness and interface asperity on the stress distribution and the cracking behavior are examined by parametric studies. The simulation results show that cracking behavior due to residual stress and interface asperity during cooling process leads to stress redistribution around the rough interface. The TGO thickness has strong influence on the maximum tensile stress of TGO and the interfacial crack development. For the sinusoidal asperities, there exist a critical amplitude above which interfacial cracking is energetically favored. For any specific TGO thickness, crack initiation is dominated by the amplitude while crack propagation is restricted to the combine actions of the wavelength and the amplitude of the sinusoidal asperity.
AB - Finite element simulations based on an interface cohesive zone model (CZM) have been developed to mimic the interfacial cracking behavior between the α-Al2O3 thermally grown oxide (TGO) and the aluminum rich Pt-Al metallic bond coat (BC) during cooling from high temperature to ambient temperature. A two dimensional half-periodic sinusoidal geometry corresponding to interface undulation is modelled. The effects of TGO thickness and interface asperity on the stress distribution and the cracking behavior are examined by parametric studies. The simulation results show that cracking behavior due to residual stress and interface asperity during cooling process leads to stress redistribution around the rough interface. The TGO thickness has strong influence on the maximum tensile stress of TGO and the interfacial crack development. For the sinusoidal asperities, there exist a critical amplitude above which interfacial cracking is energetically favored. For any specific TGO thickness, crack initiation is dominated by the amplitude while crack propagation is restricted to the combine actions of the wavelength and the amplitude of the sinusoidal asperity.
KW - Cohesive Zone Model
KW - Interface Asperity
KW - Interfacial Crack
KW - Thermally Grown Oxide
UR - http://www.scopus.com/inward/record.url?scp=84991688418&partnerID=8YFLogxK
U2 - 10.1115/GT2016-56755
DO - 10.1115/GT2016-56755
M3 - Conference contribution
AN - SCOPUS:84991688418
T3 - Proceedings of the ASME Turbo Expo
BT - Structures and Dynamics
PB - American Society of Mechanical Engineers (ASME)
CY - New York
T2 - ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition, GT 2016
Y2 - 13 June 2016 through 17 June 2016
ER -