Research On Damage Of Fretting Fatigue Of The Axle Used In High Speed Trains Under Rotating Bending

In the railway transportation, the interference fit between wheel and axle is a typical example of fretting damage, and the wheel seat of axle is the weak zone for fatigue with the impact of fretting. In this paper, aimed at fretting damage of interference fit parts between wheel and axle used in high-speed train, the fretting damage of interference fit connection under rotating bending load is investigated, through the method of small specimen test simulating fretting fatigue and finite element simulation. The main work involves:(1) According to the fretting form of railway hub and axle, rough part are cut from specific part of high-speed train axle, and machined in specimen that simulates fretting damage between wheel and axle and standard smooth cylindrical specimen. Then four points rotating bending fatigue machine is used, and the law of fretting fatigue damage of interference fit connection under rotating bending load is studied, through single point fatigue test method and fatigue interrupted test.(2) By changing the geometry of casing, so the parameters of interference fit between axle and casing is changed. Base on this, the influence of interference value, casing diameter and casing length on fretting fatigue life was investigated. In the finite element code ABAQUS, the model of different specimens was established, and the variations of parameters that effect fretting fatigue were understood, according to the test condition.(3) Notch is produced on different positions of surface of the specimens, and then four points rotating bending fatigue test was employed to test the fretting fatigue life of notch specimens. In the same time, the finite element model containing cracks with different position and depth were building, and energy method was applied to indirectly calculate the stress intensity factor of crack front. Furthermore, the relation between the stress intensity factor of the deepest point and the depth of crack was fitted, so the crack propagation life could be calculated with the help of Paris formulation.(4) The Crack Analogy Method, Ruiz criterion and Findley multi-axial fatigue criterion were analyzed to predict the fretting fatigue life in detail, and the applicability of those methods to study fretting fatigue of interference fit connection under rotating bending load was researched. (5) According the European Standard EN 13103, and aimed at non-powered axle, the ABAQUS code was used to study the influence of interference value, axle fillet radius, hub extension, diameter ratio, hollowness and temperature on contact pressure and fretting fatigue of hollow axle in detail. Findley multi-axial criterion was employed to evaluate the fretting fatigue of wheel seat and its neighboring region.