@Article{icces.2023.09927,
AUTHOR = {Guo Li, Shaochen Bao, Shuiting Ding, Zhenlei Li, Liangliang Zuo, Shuyang Xia},
TITLE = {Experimental and Numerical Methods for Characterizing Thermal  Gradient Induced Stress in Elevated Temperature Fatigue Testing},
JOURNAL = {The International Conference on Computational \& Experimental Engineering and Sciences},
VOLUME = {25},
YEAR = {2023},
NUMBER = {2},
PAGES = {1--1},
URL = {http://www.techscience.com/icces/v25n2/53828},
ISSN = {1933-2815},
ABSTRACT = {Advanced air-cooling turbine blades are capable of operating above the melting temperature of Nickel-based 
superalloy, which accordingly withstand complex thermomechanical fatigue loads during service life. This 
paper considers the problem of realizing gas turbine representative thermal gradients in the elevated 
temperature fatigue test, while ensuring the thermal gradient induced stress inside the specimens. For this 
purpose, a novel temperature control device utilizing impingement cooling, which supplies cooling air inside 
the gauge section and releases toward the inner wall, was constructed in tubular fatigue specimens. A single 
induction coil was arranged outside the gauge section, providing heat sources to establish thermal gradients 
toward the center. To accurately evaluate the temperature field in the tube, electromagnetic-fluid-thermal 
analyses was utilized, which allows taking into account influences of induction heat source and impinging 
heat transfer. Impinging flow correlation has been found, with the participation of a similarity test rig, to 
calibrate the heat transfer coefficient distribution on the inner wall of specimens. The credible temperature 
field was then introduced into a thermal-structure interaction analysis to investigate the thermal gradient 
induced stress. Ultimately, the stress distribution was studied by experimental measurements using hightemperature strain gauges. It is found that jet impingement can prominently enhance the cooling efficiency 
on the inner wall, which induces the maximum thermal gradient and tensile stress in the gauge section. In 
particular, the inside tensile thermal stress is almost inversely symmetric with the outside compressive 
thermal stress, the magnitude of which is positively correlated with the heat flux.},
DOI = {10.32604/icces.2023.09927}
}