【作者】 李敏；

【导师】 梁策； 宋相军；

【作者基本信息】 吉林大学 ， 工程硕士（专业学位）， 2023， 硕士

【摘要】 轿车控制臂衬套因橡胶材料特殊的力学特性,不仅能够弥补制造公差,还能起到传递运动和衰减振动的作用。但在汽车行驶过程中,衬套可能因表面摩擦磨损严重而出现异响、开裂和使用寿命降低等问题,最终对驾驶的稳定性和乘坐的舒适性产生不良影响。因此,本文以轿车控制臂衬套为研究对象,以大蜣螂头部的非光滑表面为仿生原型,在传统衬套表面设计并加工了仿生凸包结构,采用数值模拟方法研究不同工艺参数和凸包结构参数对衬套静、动态力学特性及柔性接触表面摩擦特性的影响规律。本文的主要研究内容与结论如下:(1)建立不同研究的有限元模型。对大蜣螂头部非光滑表面的凸包结构进行观察和提取,在传统控制臂衬套的表面设计了仿生凸包结构;基于ABAQUS平台,确定橡胶材料的超-粘弹性本构模型及其参数,并建立起符合实际工况的衬套静、动态力学特性有限元模型和衬套柔性接触表面摩擦特性的有限元模型。(2)对衬套静、动态力学特性的变化进行研究。确定衬套静、动态力学特性的评价指标,并采用刚度实验验证有限元模型的可靠性;通过仿真结果分析缩径量和仿生凸包尺寸对衬套静、动刚度和迟滞回线的影响规律。结果表明,随缩径量的增加,衬套径向和摆动静刚度的可调节范围扩大,径向和轴向动刚度逐渐增大,动静比逐渐增大;随凸包尺寸的减小,衬套的扭转静刚度逐渐增加,摆动静刚度先增加后减小,径向与轴向的动刚度和迟滞环面积都逐渐减小。(3)对仿生凸包结构的减摩减阻效果进行研究。从应力缓释、加速散热、黏着接触和黏着摩擦等方面,深入分析仿生凸包结构的减摩减阻机理,确定柔性表面摩擦特性的评价标准,并采用摩擦实验验证有限元模型的可靠性;通过数值模拟结果讨论凸包的高度、半径、间距以及排布方式对衬套柔性接触表面摩擦特性的影响规律。结果表明,仿生表面的当量摩擦系数随凸包高度和压缩量的增加而减小,随半径的增加表现为先不变后迅速增大,随间距的减小而增大,与凸包排布方式的关联性较小。更多还原

【Abstract】 Due to the special mechanical properties of rubber material,car control arm bushing can not only make up for manufacturing tolerances,but also play the role of transmitting motion and damping vibration.However,the serious friction and wear of the bushing surface leads to abnormal noise,cracking and reduced service life during the driving process of the car,which is ultimately detrimental to riding comfort and driving stability.In this paper,the car control arm bushing is taken as the object of study and the big dung beetle head’s non-smooth surface structure is taken as the bionic prototype.The bionic convex hull structure is designed and processed on the smooth surface of the standard bushing.The influence of different process parameters and convex hull structure parameters on the mechanical characteristics of the bushing and the friction characteristics of the flexible contact surface is studied by numerical simulation.The main research content and results are as follows:(1)The finite element models for different studies are established.The convex hull structure on the big dung beetle head’s non-smooth surface is observed and extracted,and the bionic convex hull structure is designed on the surface of the standard control arm bushing.The hyper-viscoelastic constitutive model and its parameters are determined.Finally,the finite element models of the mechanical characteristics of the bushing and the friction characteristics of the bushing flexible contact surface which are consistent with actual working conditions are established.(2)The changes of static and dynamic characteristics of bushing are studied.The evaluation indexes of the static and dynamic characteristics of the bushing are determined.The authenticity of the finite element model is verified by stiffness experiment.The numerical simulation results are discussed,the influence of the radial compression and the bionic convex hull size on the mechanical characteristics of the bushing is analyzed.The results show that with the increase of the radial compression,the adjustable range of the radial static stiffness and swing static stiffness of the bushing expands,the radial dynamic stiffness and axial dynamic stiffness increase,and the ratio of dynamic stiffness to static stiffness increases gradually.With the decrease of the convex hull size,the torsional static stiffness increases gradually,the swing static stiffness first increases and then decreases,the dynamic stiffness and the area of the hysteresis loop in radial and axial directions both decrease.(3)The effect of bionic convex hull structure on friction and drag reduction is studied.The friction and drag reduction mechanisms of the bionic convex hull structure are thoroughly analyzed from the aspects of stress release,accelerated heat dissipation,adhesive contact and adhesive friction.The evaluation indexes of the friction characteristics of the flexible surface are determined and the reliability of the finite element model is evaluated through friction test.The influence of convex hull height,radius,spacing and arrangement mode on friction characteristics of bionic flexible contact surface of bushing is discussed based on the simulation results.The results show that the equivalent friction coefficient of bionic surface decreases with the increase of the convex hull height and compression,increases with the decrease of the distance between the convex hulls,first stays constant and then increases rapidly with the increase of the convex hull radius,and has little correlation with the convex hull arrangement.更多还原