| Brake disc and brake lining are the important components of high-speed train disc brake system. Based on numbers of relative references, basic brake element composed of brake disc and single brake pad is used as research object; basic brake element model is established by finite element software ABAQUS; the changing regularity of brake temperature field is researched by thermo-mechanical coupling method, and is proved by experiment; the concept of equal-area brake pad shape factor is proposed, and the modal analysis of brake disc and brake lining is carried out; the effect of structure and constraint on brake disc and brake lining is researched, thereby vibration damping and noise reduction are realized. On the basis of this, the temperature field simulation of brake disc and brake lining is carried out.Fiction pair composed of common circular brake pad and brake disc is taken as research object, and simulation analysis of brake temperature field is carried out in the conditions of fixed speed and constant pressure. The simulation result shows that temperature variation curves of contact surfaces of brake disc and brake pad both have saw-toothed variation characteristic; the temperature field cloud picture of brake disc is in tail shape from start, and gradually passes to circle type, and finally spotted high-temperature areas are interconnected to form banding distribution. The temperature field cloud picture of brake pad is in tongue shape from start, and gradually becomes banded; temperature spreads to export direction, and finally radiates to the whole model along width direction. The experiment research of brake temperature field shows that the simulation temperature curve is identical to the experimental temperature curve. This indicates that the method for research using basic brake element model is feasible, and its result also reveals process essential characteristic.The concept of equal-area brake pad shape factor is proposed for the first time, that is Fs=0.0174R·θ/L. The formula not only has key element of brake pad, but also has friction radius, thus, the interaction of friction pair can be fully reflected. The shape factor describes graphic attributes; equal-area shape factor can measure the shape difference of brake pad, and can also reflect different placing position on the brake disc. The simulation results show that the smaller the shape factor of brake pad is, the lower the temperature of brake disc and brake pad is; the larger the shape factor of brake pad is, the higher the temperature of brake disc and brake pad is. The equal-area brake pad shape factor provides theoretical reference basis of brake pad shape design for designers. The effect of structure and constraint on brake disc and brake lining vibration modal is studied.the change of edge structure of brake disc structure has effects on each rank frequency of brake disc, and the effect trends are basically the same; the change of constraint is sensitive to modal effect with frequency more than 5000Hz. According to noise frequency range of actual measurement, designers can use the method of changing structure or constraint to avoid noise frequency, therefore, the purposes of vibration damping and noise reduction are achieved. After the arrangement of brake pad is changed, each rank frequency changes to some extent. In the condition of unchanged constraint quantity, the constraint effect radius of brake lining steel backing increases to 10mm from 5mm, and the modal frequency of brake lining also increases; the increase of modal frequency less than 10KHz is less, and the increase of modal frequency more than 10KHz is larger; therefore, designers can change concerned modal vibration frequency by changing arrangement of brake pad and the way of increasing constraint radius range. |
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