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Quasistatic vs. Dynamic Modulus Measurements Of Plasma-Sprayed Thermal Barrier CoatingsPlasma-sprayed 8wt% yttria-stabilized zirconia (8YSZ) thermal barrier coatings (TBCs) have been demonstrated to exhibit nonlinear hysteretic elastic behavior by quasistatic cyclic compression and cylindrical punch indentation measurements. In particular, the instantaneous (tangential) elastic modulus increases with applied stress and exhibits significant hysteresis during cycling. Sound velocity (dynamic) measurements also show an increase in TBC modulus with applied compressive stress, but in contrast show no significant hysteresis for the modulus during cycling. The nonlinear elastic behavior of the TBCs evidenced by these tests is attributed to coating compaction and internal sliding. The differences between the quasistatic and dynamic measurements are explained by the relative absence of the effect of internal sliding in the dynamic modulus measurements. By incorporating short load reversals into the larger loading cycle and measuring the instantaneous modulus at the start of each load reversal, the effects of internal sliding can be substantially reduced in the quasistatic measurements, and the resulting modulus values show good agreement with the modulus values determined by dynamic sound velocity measurements.
Document ID
Document Type
Preprint (Draft being sent to journal)
Eldridge, J. I.
(NASA Glenn Research Center Cleveland, OH United States)
Morscher, G. N.
(Ohio Aerospace Inst. Cleveland, OH United States)
Choi, S. R.
(Ohio Aerospace Inst. Cleveland, OH United States)
Date Acquired
September 7, 2013
Publication Date
January 1, 2002
Subject Category
Nonmetallic Materials
Meeting Information
26th Annual Conference on Advanced Ceramics and Composites(Cocoa Beach, FL)
Funding Number(s)
PROJECT: RTOP 714-04-20
Distribution Limits
Work of the US Gov. Public Use Permitted.
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