Research on Dynamic Mechanical Properties of Copper-zinc Alloys
In order to fit the constitutive model of copper-zinc alloy at high strain rates with high accuracy,dynamic shear tests and quasi-static tensile tests were carried out on cap specimens and tensile specimens respectively with the Hop-kinson rod(SHPB)experimental device and the electronic universal testing machine.The stress-strain curves at different strain rates were obtained,and then the Johnson-Cook constitutive model was fitted.The results showed that the copper-zinc alloy exhibited obvious strain rate strengthening and heat softening effects at high strain rate,the shear stress-strain was converted into uniaxial compressive stress-strain,and compared with the uniaxial compressive stress-strain obtained by dy-namic compression experiment,it was proved that the shear mechanical properties of copper-zinc alloy could be better reflec-ted by the cap specimen.The comparison of adiabatic temperature rise curves under different real strain rates showed that adiabatic temperature rise did not affect the rise and fall of flow stress,and temperature rise was not the only factor for the formation of adiabatic shear bands.The results of Johnson-Cook constitutive model were in good agreement with the experi-mental data,which indicated that the mechanical properties of copper-zinc alloy could be simulated effectively.
dynamic mechanical propertydifferent strain rateadiabatic temperature risecap specimensuniaxial compression stress-strainconstitutive model
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