Fatigue Stress Distibution Of The Non-power Wheel And Axle Of CRH5 Type EMU

Fatigue stressing is a basic cause to result in wheel-axle failures of railway vehicles. Possible six loading cases including extreme loadset with vertical load component of whole axle weigh and lateral load component of half axle weigh, the three loadsets of rail vehicle running on straight rail line, curved rail line, and switch by code EN 13979-1, and the maximum and minimum loadsets of vehicle running on line, are proposed for the present study. Based on the results of an integral finite canclation on non-powered wheelset of CRH 5 type EMU, fatigue stressing distribution on the wheel and axle is investigated by the stress cloud maps of von Mises stress, principale-shear stress set, and axial-radial-circular stress set. Fellow conclusions are reached:(1) Wheel tread is always subject to a statical and maximum running-contact press stressing interactive moderate surface shear stress at contact point. In addition, a moderate extreme dynamic shear stressing is companied under the sub-surface of contact point. The press stressing is far large than the yield point of the tread material and, therefore, plastic flowed damage plus wear appears always at the wheel-track contact point. And peeling damage appears probably on the tread because of the sub-surface dynamic shear stressing.(2) Below the extreme dynamic shear stress district, there is still a moderate shear stressing, and this stressing plus material defects results probably in wheel rim fracture.(3) The moderate shear stressing at the curved districts from web to rim and gub, having a value of 30 to 50 MPa, may be a cause resulting web fatigue failure.(4) Dynamic circlular stressing is the major cause possible to result in the gub failure. The tensional stress amplitude is between 30～50 MPa.(5) Curved district from axle neck to shoulder, subjected to a duplex dynamic tensional-press stressing with 40～70 MPa and and a moderate tortional shear stressing, is key location to prevent fatigue failure.(6) Outer and inner sections of wheel seat are two key districts to anti-fatigue failure of the axle. The outer section is with duplex duplex dynamic tensional-press and and moderate tortional shear stressing. The inner section is major with dynamic tensional-press stressing i n a range of 45 to 105 MPa.Present work provides a scientific guidance to analyze and prevent fatigue failures of the wheel-axle.