高铁接触网铜镁合金材料的率温耦合变形机理与本构参数

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中图分类号：0347.3 国标学科代码：13015 文献标志码：A

Abstract：Withtheincreasingspeedof trains，theimpactsofmechanical shock，archeat，andJouleheatonthehig-speed railway catenary system have become increasingly significant.The coupling efect ofhigh temperature and impact load has emerged as a key limiting factor forthesafe operation of the pantograph-catenary system.This study focuses oncoppermagnesium alloy materialsused inthecatenarysystem toaddress the chalenges ofdynamic impactand friction-induced heat generation inhigh-speedrailways.To investigate the mechanical propertiesof the high-speedrailwaypantograph-catenary systemunder service conditions such as dynamic impact and frictional temperature rise，a DF14.205Delectronicuniversal testing machine and a split Hopkinson pressure bar were employed.Theuniaxial compresionmechanical properties of the copper-magnesium alloy in the catenary were tested over a strain rate range of 0.001s-1 to 3000s-1 and a temperature range of 293K to 873K The strain-rate effect and temperature sensitivity of the stress-strain response were carefully analyzed.The study also revealed the compresson deformation mechanism and the evolution law of the aloy's microstructure under the combined influenceofstrainrateand temperature.Furthermore，adynamicconstitutive model was establishedto acurately describe the plastic flowbehaviorof thematerial.The findings indicate that duringcompresson，thecopper-magnesiumally materials exhibitsignificantstrain-rate strengtheningand temperature softening effects.These effects result from thecombied action of work hardening，strain rate，and temperature softening. When the temperature exceeds 473K ，temperature softening becomes the dominant factor in material deformation，and the elevated temperature can stimulate dynamic recoveryand dynamic recrystallzationprocesses.The modified Johnson-Cook model was found tobecapableof accurately predicting the plastic flowstres-strainresponse.Theseresearch outcomes provide valuable guidanceandreferences forthe safetydesignand evaluation of the high-speed train pantograph-catenary system during its service.

Keywords：catenarysystem; copper-magnesiumalloy;strainratesensitivity;temperature sensitivity; compresive mechanical properties; dynamic constitutive relationship

受电弓-接触网系统（简称“弓网系统”）作为高速铁路系统的关键部件，是高速列车获取能量的唯一途径[。（剩余17190字）