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A new device for restraining rail vibration of ballastless track and its effect study
Zhenxing He,Xu Zhang,Xiaotao Wang,Hualong Zhou,Quanbao Feng,Qingchao Chen,Junxia Chen,Yanbo Bai,Runxi Zhang,Nengneng Bao 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.8
A new type of rail vibration damping device (NTRVDV), which is arranged between the bottom of the rail and track bed, is proposed in this paper. The finite element model of the rail system with the NTRVDV and tuned rail damper (TRD) was established, respectively. The impact load was applied to the finite element model, and comparison of the set of existing TRD and NTRVDV on the dynamic response of rail and rail vibration decay rate. The effect of the stiffness change of the elastic layer of the NTRVDV on the rail vibration was studied, and a hammering test verified the theoretical research results. The research results show that compared with the traditional TRD, the NTRVDV has a more obvious suppression effect on rail vibration acceleration. The rail vibration decay rate is significantly improved, especially in the low-frequency stage. With the increase of the stiffness of the elastic layer of the vibration suppression device, the vibration suppression effect of the NTRVDV on the rail is improved. The change of the elastic layer stiffness significantly impacts the rail’s vibration suppression effect in the range of 0-7 kN/mm.
Huo Guoyan,Su Qian,Li He,Li Zhenxing,Chang Yating 한국물리학회 2020 Current Applied Physics Vol.20 No.6
The effect of oxygen deficiency and oxygen excess on the magnetic and electrical transport properties of La0.67Sr0.33MnO3 has been investigated. The thermal and isothermal magnetization measurement results show that the Curie temperature and saturation magnetization of oxygen deficient sample (defined as A) are higher than those oxygen excess sample (defined as B). The electrical resistivity of A is lower than that of B in studied temperature range. The magnetoresistance (MR) of B is larger than that of A in the temperature range from 280 to 360 K, which agrees with the magnetic field needed full spin polarization at room temperature. The colossal MR (CMR) around transition temperature from ferromagnetic metal to paramagnetic insulator (TMI) for A is larger than that for B, which arises from assistance of stronger lattice deformation for A.