Determination of the Drucker-Prager parameters of polymers exhibiting pressure- sensitive plastic behaviour by depth sensing indentation.

R SELTZER; FRONTINI, PATRICIA; ADRIÁN CISILINO; YIU-WING MAI

INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2011 vol. 53 p. 471 - 478

0020-7403

This paperpresentsamethodtodeterminetheDrucker–Pragerparametersofpressure-dependantelastic-perfectlyplasticpolymericmaterialsbymeansofthedepth-sensingindentationtechnique.Thisis achievedviaaninverseanalysisoftheload–displacementdataresultingfromtwotestsperformedwith Berkovichandsphericaltips.Thewell-posednessandtheeffectiverangeofapplicationoftheproposedmethodarecarefullyassessedfirst.Thenthemethodistestedfortwoelasto-plasticmaterialswith mildinitialstrain-hardening(HDPEandPMMA),andtheresultsarecomparedtothosemeasuredusing conventionaltensileandcompressiontests.Itisfoundthatthepressure-sensitivityindicescanbeaccuratelypredicted,whiletheyieldstresspredictionsintensionandcompressionfallwithinthenon-linear portionoftheuniaxialstress–straincurves,i.e.,insidetheregionwhereplasticdeformationbegins.