Can stress-strain relationships be obtained from indentation curves using conical and pyramidal indenters?

Applying the scaling relationships developed recently for conical indentati on in elastic-plastic solids with work-hardening, we examine the question o f whether stress-strain relationships of such solids can be uniquely determ ined by matching the calculated loading and unloading curves with that meas ured experimentally. We show that there can be multiple stress-strain curve s for a given set of loading and unloading curves. Consequently, stress-str ain relationships may not be uniquely determined from loading and unloading curves alone using a conical or pyramidal indenter.