We propose an improved technique to determine the uniaxial residual stress, elastic modulus, and yield stress of a linear elastic, perfectly plastic bulk material from the force-displacement curve of one conical indentation test. Explicit relationships between the indentation loading-unloading parameters, material properties, and residual stress are established through extensive finite element analyses. Good agreement is found between the input material parameters used in numerical indentation tests and the properties identified from the reverse analysis, with an error of less than 10% in most cases. The technique is applied to a nanoindentation experiment on the cross-section of a thermal barrier system, to measure the elastic-plastic behavior and the residual stress in the bond coat. Likewise, the improved method may be used to measure effectively the material properties and uniaxial residual stress of a multilayer system. © 2006 Acta Materialia Inc.
Bibliographical noteThe work of M.Z. and X.C. is supported by NSF CMS-0407743. The work of J.Y. and A.M.K. is supported by NSF DMR-0346664 and ONR N00014-04-1-0498. We thank Professor Christopher Schuh’s group at the Massachusetts Institute of Technology for aiding in the nanoindentation tests and Dr. Ing. Marion Bartsch’s group at the German Aerospace Center (DLR), Cologne, Germany, for providing the samples.
- Finite element analysis
- Mechanical properties
- Residual stresses