Study on dynamic mechanical response of a polymer bonded explosive under high strain rates

摘要

Dynamiccompressivestress-straincurvesofapolymerbondedexplosive(PBX)athighstrainrates(from403s-1to2207s-1)havebeendeterminedwithamodifiedsplitHopkinsonpressurebar(SHPB).PulseshapingwasusedtoensurethatthePBXspecimendeformsatanearlyconstantstrainrateunderdynamicallyequilibratedstress.Anearlyconstantstrainrateunderdynamicallyequilibratedstresswasprovidedbasedonthepulseshaping.Thelaserdisplacementmeterwasusedtomonitortheaxialstrainofthespecimenintheexperiments.Thevalidityoftheexperimentswasmonitoredbythepolyvinylidenefluoride(PVDF)forcesensorsfordynamicstressequilibrium,andbyahigh-speedcameraforspecimendeformation.Allresultsindicatethatthematerialissensitivetostrainrateandthestrain-ratesensitivitydependsonthevalueofstrain,andthecompressivestrengthimproveswiththeincreaseofRDXcontent.