Experimental Study On Fatigue Performance Of WJ-7 Type Ballastless Track Fastener Spring Clip

Fasteners to play as an important component of railway track,using elasti c deformation when the energy stored by have played an important role in ease the mechanical vibration and shock,prevent the rail vertical and horizontal displacement of the rail and rail structure under long-term effectively connected into a whole.Rail system because of the train operation process of the complex and changeable load,make the fastener system under the dynamic load to bear for a long time,the periodic bending and reverse the effect of alternating stress,thus caused a fastener plays a ser ies of fatigue problemsFirst article to study the play its stress and displacement in the process of fatigue test,the change rule of reference standard "play ?,? fastener article elastic fatigue test method of elastic fatigue test method and combined wi th in this paper,the re search content,design a kind of applicable to general axial loading fatigue testing machine test fixtures,as well as the design and construction of the form a complete set of two pressure sensors and three displacement sensor,use d to play a real-time acquisition plays in the process of fatigue test of the stress and displacement,with a higher precision instrument sensor performance test,the results show that its performance meet the requirements,the practice shows that the designed test fixture is feasible.Then established the simplified WJ-7 type fastener system model,adopt the method of numerical simulation and resistance strain testing method to analysis the stress distribution under article play installation,studies have shown that article elastic stress distribution under different load,and to determine the article elastic fracture risk point location for play and with end to end on both sides of the bend.Then the WJ-7 type fastener W1 type play article conducted in different load amplitude and displacement amplitude of fatigue test,based on the distribution of the F-N statistical reliability research,studies have shown that the lower the load amplitude(the amplitude of displacement)is,the greater the fatigue life and the change in the amplitude of the smaller load(the amplitude of the displacement)will cause a great change in the fatigue life of the projectile.Through the analysis of elastic buckle law of stress and fatigue life cycle curve,article predicted the life of Spring clip by the Linear cumulative damage model according to the fatigue cumulative damage theory and the introduction of variable D(pressure damage than article play button),r esults showed that the predicted life close to the measured life overall.Finally through hardness test,the article from the perspective of the hardness,the play of fatigue fracture location,combined with static analysis of the stress distribution,show that between 44 HRC ~ 47 HRC hardness when the fatigue life of the best.Through macroscopic analysis of fracture,it shows that it belongs to bending and torsion fatigue load fracture.The failure mechanism of fatigue fracture was analyzed by SEM.