铜基粉末冶金摩擦材料冲击时的动态力学特征(英文)

Mechanical property of Cu-base powder metallurgy friction material under impact load

在分离式Hopkinson压杆(SHPB)上做了铜基粉末冶金摩擦材料在102s-1～103s-1应变率范围内的冲击试验,弹速范围为4m/s～15m/s,在透射杆上采用了半导体应变片技术;在MTS实验机上做了该材料在10-4s-1～10-3s-1应变率范围内的准静态实验,分别在应变为0 005,0 010,0 020,0 035时卸载再加载,以验证材料的黏弹塑性特征.通过分析动态和静态实验曲线,发现该材料在应变率300s-1和准静态时有应变硬化效应,但在应变率500s-1以上却反映出应变软化效应,因此该材料为含损伤非线性黏弹塑性材料.该结论可推广应用于类似烧结合金的材料,实验给出的 Receiveddate:2003-08-21 Foundationitem:ItissupportedbyChinaAcademyofEng.PhysicsFund(421010201);OutstandYoungFundofHe′nanProvince;Im portantIndustryProjectofHe′nanProvince(03230239000) Authorbiography:LIUJian＿xiu(1962—),female,wasborninHongtongCounty,ShanxiProvince,Professor,ZhengzhouInst.ofLightInd.,ChinaAcademyofEng.PhysicsDr.,themainresearchinterestwascomputationalMech.andEng.dynamics. 第1期LIUJian xiuetal:MechanicalpropertyofCu＿basepowdermetallurgyfrictionmaterialunderimpactload·15· 该材料动态和静态数据,为工?

The dynamic and quasi-static stress-strain relationship of powder metallurgy (Cu-PM) had been studied experimentally.Dynamic tests were made at strain rate 10~2 s^(-1)～10~3 s^(-1) by split Hopkinson pressure bar(SHPB),with bullet speeds of 4 m/s～15 m/s,and semiconductor gage was used on the transmitted bar.Quasi-static measurements were made at strain rate 10^(-4) s^(-1)～10^(-3) s^(-1) by MTS machine.Reload tests were conducted at strain 0.005,0.010,0.020,0.035,respectively,to investigate the visco-elastic plastic characteristics.Analysis of dynamic and static test curve shows that the material exhibit strain under strain rate of (300 s^(-1)) however,negative strain effect was observed under strain rate of 500 s^(-1).Therefore it is damage weakening non_linear glutinous elasto_plastic material.The condusion can be applied to sintered alloy.The dynamic and static data lay firm foundation on engineering design.