Lee and Radok [J. Appl. Mech. 27, 438 (1960)] derived the solution for the indentation of a smooth rigid indenter on a linear viscoelastic half-space. They had pointed out that their solution was valid only for regimes where contact area did not decrease with time. In this article, a large number of finite element simulations and one typical experiment demonstrate that Lee-Radok solution is approximately valid for the case of reducing contact area. Based on this finding, three semiempirical methods, i.e., Step-Ramp method, Ramp-Ramp method and Sine-Sine method, are proposed for determination of shear creep compliance using the data of both loading and unloading segments. The reliability of these methods is acceptable within certain tolerance.[DOI:10.1557/jmr.2012.120]

This paper was published as:
Peng GJ;Zhang TH;Feng YH;Yang R. Determination of shear creep compliance of linear viscoelastic solids by instrumented indentation when the contact area has a single maximum. JOURNAL OF MATERIALS RESEARCH, 27(12):1565-1572 (2012)