通风盘式制动器制动盘的寿命预测分析

制动器是汽车制动系统的核心部件,在实际制动过程中,制动盘会产生比机械应力大很多的热应力。制动盘承受的由压应力、拉应力及摩擦导致的热应力组成的交变载荷,它们的共同作用会使制动盘表面产生裂纹,当裂纹扩展到一定程度后．可能导致整个制动盘断裂失效。制动盘的疲劳试验难度较大且需要大量的时间,因此应用数值模拟方法进行仿真分析并预测其使用寿命是非常必要的。以某型通风盘式制动器为例,在应用非线性有限元方法对制动过程进行热一力耦合分析结果的基础上．根据Malison—Coffin公式预测制动盘的热疲劳寿命．并分析制动初速度和制动压力对制动盘使用寿命的影响。     

汽车鼓式制动器热力耦合有限元仿真分析

针对大坡度路段装载有鼓式制动器的重型载重汽车下坡时事故频发的问题,对某后桥单驱动鼓式制动器在制动过程中的温度和应力变化进行了研究。使用了有限元分析方法,对汽车鼓式制动器的制动鼓、制动蹄和摩擦衬片进行了热分析求解和结构分析,将温度场运算结果附加到模型之中,并求解了制动器结构的应力分布,对其进行了热力耦合分析;使用ANSYS workbench建立了鼓式制动器热力耦合有限元模型,通过制动摩擦生热模拟仿真试验对热力耦合作用进行了15次分析。研究结果表明:制动鼓、制动蹄及摩擦片的升温变化明显,通过监测确定了热衰退临界温度临界点。     

基于受力分析的制动鼓耦合分析

针对制动鼓在使用过程中出现的因温度上升而引起的摩擦系数非稳定性下降、制动力矩降低以及因热应力导致的制动鼓表面出现径向裂纹,致使制动鼓断裂失效等问题,基于对制动鼓的受力分析,将结构和受力情况比较复杂的制动鼓模型进行了有效地简化,并建立了模型,采用有限元分析法得出了在150℃时制动鼓的位移分布图和热应力分布图,以及在不考虑热效应下的位移和应力分布图。通过对制动鼓外侧、内壁及摩擦片接触区域的耦合分析,检验了在机械载荷和热载荷共同作用下,制动鼓的最大应力与材料强度极限之间的关系。研究结果表明,尽管温度对制动鼓的变形和强度有很大影响,制动鼓的强度要求仍然能够被满足,研究结果为制动鼓的结构优化及进一步的系统动力分析奠定了基础。     

基于ANSYS的制动鼓热应力耦合仿真分析

运用ANSYS技术对汽车制动器制动鼓进行了持续制动温度分布仿真分析,分别对制动鼓在结构载荷作用下、热载荷作用下及热载荷与结构载荷作用下进行了仿真分析,并对结果进行了对比,在相同条件下,双载同时作用下制动鼓产生的最大应力比单独载荷作用下要大得多,为制动鼓设计提供了一种工程方法。     

表面织构对制动鼓制动热的影响

基于热力耦合原理,运用有限元软件ABAQUS建立鼓式制动器制动热模型。分析无表面织构和三种不同表面织构的制动鼓的制动温度场及应力场分布。研究结果发现:制动过程是一个快速升温,缓慢降温的过程,制动鼓内表面温度与应力的变化趋势一致。三种表面织构最高温度和无织构制动鼓的最高温度一样,但是制动结束后,无沟槽制动鼓和径向沟槽制动鼓的温度和应力变化趋势相似,环形沟槽制动鼓和复合沟槽制动鼓的温度和应力变化趋势相似;四种制动鼓的最大弹性应变能比排序依次为无沟槽制动鼓,径向沟槽制动鼓,环形沟槽制动鼓和复合沟槽制动鼓,说明这四种制动鼓的散热效果亦如上面的排序。     

制动器的保护神：电涡流缓速器

良好的制动性能是车辆安全行驶的重要保证。传统车辆制动方式是采用在车轮上安装机械式摩擦制动器,但这种摩擦式车轮制动器存在一个重大缺陷：频繁或长时间制动会造成制动鼓（盘）和摩擦衬片过热,导致制动效能衰退,甚至制动失效,从而引发重大交通事故。     

叉车制动时制动鼓温升的计算与分析

建立了制动鼓在紧急制动状态下非稳态有限差分计算热模型，推导出内部节点和表面节点温度的有限差分计算公式，并对制动鼓温升进行了实际计算，说明制动初速度、摩擦衬片宽度及制动鼓厚度对制动鼓温度分布的影响。     

颗粒阻尼用于鼓式制动器减振降噪

分析了颗粒阻尼用于鼓式制动器减振降噪的可行性,并对其阻尼特性进行了试验研究.建立某鼓式制动器的有限元模型,在考虑摩擦衬片和制动鼓之间摩擦接触的情况下,计算了当制动鼓周缘具有填装颗粒的孔洞时在制动工况下制动鼓的应力状况.向制动鼓周缘的孔洞填充不同材料、不同填充比的颗粒,通过试验获得静态下制动鼓模态阻尼比随颗粒参数的变化情况.结果表明,颗粒阻尼器可有效提高制动鼓的模态阻尼比,具有良好的减振降噪效果.     

卡车制动鼓摩擦扭矩试验机

制动鼓摩擦扭矩试验机是对汽车刹车制动鼓进行高温摩擦扭矩试验的专用机床,可进行内径400～420mm的制动鼓摩擦扭矩的试验,最大扭矩可达到14000N·m,最高温度可达到380℃,有效地保证了卡车制动鼓在高温和大扭矩下不产生疲劳断裂,保证了制动鼓的出厂质量和行车安全。     

车轮抱死时鼓式制动器强度的数值分析

以有限单元法为基础,利用ANSYS软件得到了车轮抱死时鼓式制动器的强度分布.所建立的模型利用接触考虑了制动鼓和摩擦衬片间的相对滑动趋势,较真实的模拟了制动器的工作过程;得到了摩擦衬片、制动蹄和制动鼓上的应力大小和接触面上应力的分布特性.从而为摩擦衬片厚度的设计和鼓式制动器结构的改进提供了理论依据.     

制动摩擦副材质对其摩擦性能影响的研究

对有机石棉和半金属衬片材料与不同化学组分的灰铸铁制动盘（鼓）进行摩擦性能试验。分析了对偶材质对衬片磨损及摩擦系数的影响及衬片材质对制动盘（鼓）磨损的影响。提出了评定衬片材料的耐磨性必须标明对制动盘（鼓）的损伤及制动副材料的最佳选配问题。     

Analysis of stir die cast Al–SiC composite brake drums based on coefficient of friction

The work reported here is to analyze the suitability of Aluminum alloy–Silicon Carbide MMC (Al–SiC MMC) in the automobile brake drum applications in comparison with cast iron (CI) brake drum. A brake drum dynamometer test rig was developed for the purpose. Al–SiC MMC was reinforced with 10% and 15% SiC particle by weight. The effect of heat treatment of the Al–SiC MMC brake drum was also studied. Performance was mainly evaluated on the basis of brake drum coefficient of friction (μ). Scanning electron microscope was also used to study the effect of braking on the sliding surface of the brake drum.     

盘式制动器摩擦磨损热动力学研究进展

摩擦磨损热动力学是制动器失效分析和设计的重要理论依据,对选择摩擦副材料也有指导作用．因此从分析摩擦热对制动器摩擦副的影响着手,总结了盘式制动器摩擦磨损热动力学的数学、物理模型,并对制动摩擦表面温度场和应力场的计算方法进行分析比较,评述了盘式制动器摩擦磨损热动力学的研究进展,并对今后主要研究工作进行了展望．     

惯性制动条件对铜-石墨材料摩擦性能及第三体的影响

采用粉末冶金技术制备铜-10%石墨烧结材料,通过GF150D型摩擦试验机,在干摩擦状态及制动压力为0.51 MPa的条件下,研究不同制动方式对材料摩擦磨损性能的影响。结果表明,采用从高速到低速分段制动方式(摩擦方式A)时,随着制动速度降低,摩擦表面形成的致密第三体破碎、剥落,机械啮合力增加,摩擦因数提高;同时,摩擦表面温度下降,基体强度提高,磨损率降低。采用从高速到低速连续制动方式(摩擦方式B)的摩擦因数和磨损量均大于摩擦方式A。     

Simulation of Temperature Distribution in Disk Brake Considering a Real Brake Pad Wear

This paper presents a methodology for the modeling of the transient thermal behavior of the disk brake of the vehicles using finite element methods. The influence of the wear properties of friction materials on thermoelastic behaviors is investigated to facilitate the conceptual design of the model. The coupled characteristics of the friction heat flow between the disk and pad as well as the effects of the brake disk thermal stress because of the variable applied pressure was considered. At the same time, the model was optimized by the experiment. Repeated brake processes with varying load, sliding speeds and temperature are applied in the simulation of the disk brakes. Experimental dependencies of the coefficient of friction and wear rate on the temperature of brake pad were approximated and applied to the model. The temperature and pressure on the contact surface of the pad/disk brake system obtained for constant and speed/pressure sensitivity applications were confronted and compared. The thermo-distribution is operated to visualize the disk temperature.     

Influence of Thermal Fatigue on the Wear Behavior of Brake Discs Sliding against Organic and Semimetallic Friction Materials

ABSTRACT

In this article, brake discs are exposed to high thermal stress, causing thermal fatigue damage. The aim of this work is to study the evolution of the wear behavior of brake disc materials, such as cast iron, chromium steel, and metal matrix composites, under the influence of thermal fatigue. The brake disc specimens are heated and then cooled rapidly. Then, wear tests are carried out using a pin-on-disc-type tribometer. Organic and semimetallic friction materials are used for all wear tests. The results show that thermal fatigue affects the structure of the contact surfaces of all of the disc specimens by increasing their roughness. Furthermore, the wear rate of the friction materials increased, except a reduction of the wear rate is noted for the semimetallic friction material rubbing against cast iron. Moreover, thermal fatigue has no significant influence on the coefficient of friction. The worn surface of the metal matrix composite sliding against semimetallic friction material is characterized by abrasive and adhesive wear mechanisms.     

车轮钢摩擦副滚动摩擦磨损特性研究

在NENE-2型磨损试验机上利用往复滚动试验装置研究了不同制动状态下车轮钢的滚动摩擦磨损特性。结果表明:不同滚滑状态下的切向摩擦力是变化的,随制动力的增加,滚动摩擦副对应的摩擦因数和摩擦阻力相应增大;平面试样的表面磨痕形貌由于切向摩擦力的变化而明显不同;随切向摩擦力的增大滚动磨损机制亦发生改变,从磨粒磨损逐渐转变为粘着磨损,磨损加剧且磨痕深度变大。     

Friction and wear of sintered metallic brake linings on a C/C-SiC composite brake disc

The friction and wear of sintered metallic brake linings on a C/C-SiC composite brake disc were studied. This paper reports on the friction and wear properties of sintered metallic (MMC) brake linings, which appear to combine well with a C/C-SiC brake disc. The friction characteristics were examined with a dynamometer on two different commercial motorcycle brake systems, differing in terms of the brake caliper and the dimensions of the disc. The influence of the components, such as graphite, and the abrasives in the metallic matrix on the formation of the friction layer was investigated using a scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX). The friction layer formed on the pad's sliding surface by oxidation wear, which consisted mostly of iron and copper oxides, was confirmed. The friction properties of the sintered metallic brake pads were determined and related to the composition and structure of the brake lining. This investigation of the friction characteristics of a brake couple comprising (MMC) brake linings and a C/C-SiC composite disc will increase our understanding of this material, which works in a completely different way to classical brakes based on metallic discs.