重型车辆织构化刹车系统热力学行为与摩擦学性能研究

Thermodynamic Behavior and Tribological Performance of Textured Brake System in a Heavy Vehicle

重型车辆刹车系统受瞬态高温和雨水异常侵入的影响,易引起热力学行为与摩擦性能退化。为研究表面织构对刹车系统热力学行为和摩擦学特性的影响,基于有限元法开展刹车系统热力学分析,考虑大量雨水侵入的液体润滑极端情况,提出一种动压润滑与织构集成模型的摩擦学性能分析方法。结果表明:水平凹槽织构可使制动盘温度场及应力场分布较均匀,进而避免接触区域局部瞬态高温引起的车辆制动失效;随着凹槽织构倾斜角度增大,承载力增大,摩擦因数减小;不同组合型织构中,圆柱与椭球组合型织构表面承载力最大、摩擦因数最小,圆锥与椭球组合型织构表面承载力最小、摩擦因数最大。研究发现重型车辆刹车系统表面构筑合适倾斜角度凹槽织构和组合型织构有助于提升其工作性能。

The transient high temperature and water intrusion can easily lead to the degradation of thermodynamic behavior and braking performance of the brake system of heavy vehicles.To investigate the influence of surface texture on the thermodynamic behavior and tribological characteristics of brake systems,the thermodynamic analysis of the brake system was carried out based on the finite element method,and considering the extreme case of liquid lubrication in brake systems as a large amount of water intrusion,an improved lubrication analysis model of the textured brake system was established.The results show that the horizontal groove texture of the brake lining can make the temperature and stress distribution of the brake disc more uniform,thereby avoiding the occurrence of vehicle brake failure caused by local high temperature in the contact area.With the increase of the groove inclination angle,the load capacity increases and the friction coefficient decreases.For the different combination textures types,the cylindrical and ellipsoidal combined textures have the highest surface bearing capacity and the lowest friction coefficient,while the taper and ellipsoidal combined textures have the lowest surface bearing capacity and the highest friction coefficient.It is helpful to improve the working performance of the brake system in a heavy vehicle by constructing groove texture and combination texture on the brake lining surface.