【作者】 王玉；

【导师】 邵毅敏；

【作者基本信息】 重庆大学 ， 机械工程， 2017， 硕士

【摘要】 摩擦片作为盘式离合器元件,通过摩擦来传递动力;作为制动器主要元件,通过摩擦吸收动能和制动;使机械设备与各种机动车辆能够安全可靠地工作。因此,摩擦片是一种关键的构件,广泛运用于刹车制动系统和离合传动系统。摩擦片的损伤形式有:摩擦材料磨损、黏着损伤、芯板断裂、翘曲变形、摩擦片烧伤破坏等。由于扭振等引起的内毂速度波动,造成摩擦片与内毂发生冲击碰撞,摩擦片齿部受到碰撞力,诱发摩擦片轮齿的齿面与齿根损伤等,严重影响摩擦片寿命和工作稳定性。论文针对摩擦片与内毂冲击碰撞过程中的齿根损伤,主要研究其疲劳损伤的定量评估方法。论文的主要研究内容如下:1)建立了摩擦片与内毂三维实体模型,运用MSC Adams对摩擦片碰撞力进行动力学仿真分析,获得摩擦片与内毂动态碰撞力,以及不同波动速度、不同压力角、不同模数齿数对摩擦片碰撞力的影响规律;同时,建立摩擦片与内毂有限元模型,施加碰撞力,采用ANSYS瞬态分析方法,获得摩擦片齿根应力;为摩擦片碰撞力控制和损伤分析提供了基础数据。2)为了改善齿根应力分布,提出了齿部开孔的方法,建立了不同形状,不同孔大小开孔摩擦片模型,通过动力学仿真和ANSYS瞬态分析,研究了摩擦片开孔形状与开孔大小对摩擦片齿根应力的影响规律,为摩擦片齿根应力控制提供了一种新的方法。3)针对非线性损伤定量评价的问题,提出了摩擦片冲击应力衰减门槛值累积损伤非线性评估方法,分析了不同仿真工况下摩擦片的损伤定量评价以及寿命计算,为摩擦片损伤评价奠定了理论基础。4)针对评价方法的有效性和可靠性,采用高速摄影系统对摩擦片与内毂冲击动态过程进行分析,获得了摩擦片与内毂动态冲击特征;运用动态应变测试方法获得齿部动态齿根应力变化特征;采用三维超景深显微系统分析摩擦片的损伤;试验结果验证了摩擦片齿根应力计算方法和摩擦片冲击应力衰减门槛值累积损伤非线性评估方法的有效性。更多还原

【Abstract】 Friction plate is a key part of clutches,it transmits power through friction,it is also the main element of brakes,absorbing the kinetic energy through friction.Friction plate make mechanical equipment and all kinds of motor vehicles work safely and reliably,thus the friction plate is a key component widely used in brake system and transmission system.The friction plate is composed of the core plate and the friction material,its damage forms are: the friction material wear,the adhesion damage,fracture of core plate,warping deformation,burning and so on.Because of speed fluctuation of the inner hub caused by torsional vibration,friction plate is under impact collision of inner hub,the impact load causes tooth surface and the tooth root damage to the friction plate,and effects the lifetime and stability of friction plate.The paper is mainly trying to study the damage of tooth root devoted by impact load and its quantitative evaluation method.The main research work includes:1)A three-dimensional model of the inner hub and friction plate were set up.MSC Adams software were used to build their multi-body dynamics model later,through dynamic analysis,the impact load force of frictional plate and inner hub with different parameters,including backlash,pressure angle,module and number of teeth were obtained.Later,tooth root stress of friction plate with those different parameters were obtained using ANSYS transient analysis,Providing the basic data for the friction plate impact force control and damage analysis.2)To control tooth root stress,dynamic models and finite element models of different sizes and shapes of holes arranged on friction plate were built,through dynamic analysis and transient analysis.The influence of holes on the tooth root stress was obtained,providing a new way to control the stress of friction plate.3)To evaluate the damage of friction plate quantitatively,a non-linear damage evaluation method which accumulate stress cycles with amplitude larger than the threshold value was proposed,lifetime of friction plate with different parameters and different sizes and shapes of holes were calculated,laid the theoretical foundation for the evaluation of friction damage.4)Aimed at the effectiveness reliability of the damage evaluation method,high-speed photography system was used to study the dynamic impact process between the friction plate and the inner hub,dynamic impact characteristics was obtained;Dynamic strain test method was used to measure the dynamic tooth root stress;Three-dimensional super depth microscopic system was used to check the fatigue failure condition of friction plate.Test results validate the accuracy of the tooth root stress calculation method and reliability of the damage evaluation method.更多还原