摘要
采用内聚力模型和热生长氧化层(TGO)非均匀增长子程序,数值模拟了在热循环载荷作用下热障涂层(TBC)内部应力演化规律和开裂行为。涂层失效过程首先是源自陶瓷层(TC)内近波峰位置的拉伸和切应力共同主导的陶瓷层Ⅰ、陶瓷层Ⅱ混合型裂纹;随着循环数增加,则转向由TC内近波峰位置的切应力主导的Ⅱ型裂纹和波峰波谷中间的涂层厚度方向拉伸应力主导的Ⅰ型裂纹。整体非均匀增长和波谷均匀增长模式下的最大拉伸应力经过一定循环数后几乎不再随循环数而增加;而在波峰均匀增长和整体均匀增长模式下,最大拉伸应力则会随着循环数增加持续增长。整体非均匀增长、波谷非均匀增长模式下,20个循环后最大切应力出现在近波峰位置,分别为-162.41 MPa和-154.28 MPa;而整体波峰均匀增长和整体均匀增长模式下,最大切应力为-113.82 MPa和-111.98 MPa。对于波谷均匀增长和整体非均匀增长模式,在9个循环后出现界面裂纹。而对于波峰均匀增长和整体非均匀增长模式,在第17个循环出现界面裂纹。
The cohesive force model and the thermal growth oxide(TGO)non-uniform growth subroutine were used to numerically simulate the stress development and cracking behavior of the thermal barrier coating(TBC)under thermal cycling loading.The cracking process was firstly caused by the mixedⅠandⅡcracks due to the tensile and shear stress in the near peak position in the top coat(TC);it turned to the modeⅡcrack due to the shear stress near the peak of the TC and the modeⅠcrack due to the tensile stress in the thickness direction in the middle of the peak and trough with the increasing number of thermal cycles.The maximum tensile stress in the overall non-uniform growth and the valley uniform growth mode almost did not increase with the number of cycles after some cycles;while in the peak uniform growth and the overall uniform growth mode,the maximum tensile stress increased continuously.In the global non-uniform growth mode and the valley non-uniform growth mode,the maximum shear stress of-162.41 MPa and-154.28 MPa appeared at the position near the peak after 20 cycles;while in the global uniform wave growth and global uniform growth mode,the maximum shear stress were-113.82 MPa and-111.98 MPa,respectively.For the uniform growth of the valley and the overall non-uniform growth mode,interface cracks appeared after 9 cycles;while for the uniform peak growth and overall non-uniform growth mode,interface cracks appeared in the 17 th cycle.
作者
刘扬
全昌彪
杨晓光
石多奇
张生良
孙燕涛
宋佳楠
李少林
LIU Yang;QUAN Changbiao;YANG Xiaoguang;SHI Duoqi;ZHANG Shengliang;SUN Yantao;SONG Jianan;LI Shaolin(Aero Engine Corporation of China,Zhuzhou Hunan 412002,China;School of Energy and Power Engineering,Beijing University of Aeronautics and Astronautics,Beijing 100191,China;Beijing Key Laboratory of Aero-Engine Structure and Strength,Beijing University of Aeronautics and Astronautics,Beijing 100191,China;Beijing Aeronautical Engineering Technical Research Center,Beijing 100076,China)
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2020年第6期1140-1148,共9页
Journal of Aerospace Power
